
<PAGE>

                                                                    Exhibit 10.3

                                  $100,000,000

                               ANTEON CORPORATION

                     12% SENIOR SUBORDINATED NOTES DUE 2009

                               PURCHASE AGREEMENT

                                                                     May 6, 1999

CREDIT SUISSE FIRST BOSTON CORPORATION
DEUTSCHE BANK SECURITIES INC.,
LEGG MASON WOOD WALKER, INCORPORATED
  c/o Credit Suisse First Boston Corporation
  Eleven Madison Avenue,
  New York, N.Y. 10010-3629

Dear Sirs:

      1. INTRODUCTORY. Anteon Corporation, a Virginia corporation (the
"COMPANY"), proposes, subject to the terms and conditions stated herein, to
issue and sell to the several initial purchasers named in Schedule A hereto (the
"INITIAL PURCHASERS") U.S.$100,000,000 principal amount of its 12% Senior
Subordinated Notes Due 2009 (the "NOTES"). The Notes will be unconditionally
guaranteed on a senior subordinated basis by Vector Data Systems, Inc. and
Techmatics, Inc., each a Virginia corporation (the "SUBSIDIARY GUARANTORS"), and
each subsequently organized domestic subsidiary of the Company (such guaranties,
together with the Notes, the "OFFERED SECURITIES"). The Offered Securities will
be issued under an indenture dated as of May 11, 1999 (the "INDENTURE"), among
the Company, the Subsidiary Guarantors and IBJ Whitehall Bank & Trust Company,
as trustee (the "TRUSTEE"). The United States Securities Act of 1933 is herein
referred to as the "SECURITIES ACT".

      The Offered Securities are being issued and sold in connection with (i)
the consummation of the acquisition (the "ACQUISITION") of all shares of common
stock issued and outstanding of Analysis & Technology, Inc., a Connecticut
corporation ("A&T"), pursuant to an agreement and plan of merger dated March 7,
1999, among the Company, Buffalo Acquisition Corporation, a Connecticut
corporation and a wholly-owned subsidiary of the Company ("BUFFALO"), and A&T
(the "MERGER AGREEMENT") and (ii) the refinancing of all existing bank
indebtedness of the Company and A&T. To consummate the Acquisition and the
refinancing, (1) the Company will issue the Offered Securities, (2) the Company
will enter into a credit agreement in an aggregate principal amount of $170.0
million (together with related guarantees and security agreements, the "CREDIT
AGREEMENT") and (3) Caxton-Iseman Capital, Inc. and/or an affiliate
(collectively, "CIC") will contribute or cause to be contributed not less than
$22.5 million in cash in exchange for an equity interest in the Company. The
consummation of the Acquisition is expected to occur in June 1999.

      On the Closing Date (as defined below), the net proceeds from the sale of
the Offered Securities (the "ESCROW FUNDS") will be deposited with IBJ Whitehall
Bank & Trust Company, as escrow agent (the "ESCROW AGENT"), pursuant to the
terms of an escrow agreement (the "ESCROW AGREEMENT"). The Escrow Funds shall be
withdrawn and paid out pursuant to the terms of the Escrow Agreement.

      Holders (including subsequent transferees) of the Offered Securities will
be entitled to the benefit of a Registration Rights Agreement of even date
herewith (the "REGISTRATION RIGHTS AGREEMENT"), among the Company, the
Subsidiary Guarantors and the Initial Purchasers, pursuant to which the Company
will be obligated to file with the Securities and Exchange Commission (i) a
registration statement under the Securities Act registering an issue of senior
subordinated notes of the Company (the "EXCHANGE NOTES") which shall be
identical in all material respects to the Offered Securities (except that the
Exchange Notes will not contain terms with respect to transfer restrictions) and
(ii) under certain circumstances, a shelf registration statement pursuant to
Rule 415 under the Securities Act.
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      This Agreement, the Registration Rights Agreement, the Indenture and the
Escrow Agreement are referred to herein collectively as the "OPERATIVE
DOCUMENTS". The Merger Agreement, all other operative agreements relating to the
Acquisition and CIC's equity contribution, if any, and the Credit Agreement are
referred to herein collectively as the "TRANSACTION DOCUMENTS".

      The Company and the Subsidiary Guarantors hereby agree with the several
Initial Purchasers as follows:

      2. REPRESENTATIONS AND WARRANTIES OF THE COMPANY AND THE SUBSIDIARY
GUARANTORS. The Company and the Subsidiary Guarantors jointly and severally
represent and warrant to, and agree with, the several Initial Purchasers that:

            1. A preliminary confidential offering circular and a confidential
      offering circular relating to the Offered Securities to be offered by the
      Initial Purchasers have been prepared by the Company. Such preliminary
      offering circular and offering circular, as supplemented as of the date of
      this Agreement, together with any other document approved by the Company
      for use in connection with the contemplated resale of the Offered
      Securities are hereinafter collectively referred to as the "OFFERING
      DOCUMENt". As of its respective dates, the Offering Document does not
      include any untrue statement of a material fact or omit to state any
      material fact necessary in order to make the statements therein, in light
      of the circumstances under which they were made, not misleading. The
      preceding sentence does not apply to statements in or omissions from the
      Offering Document based upon written information furnished to the Company
      by any Initial Purchaser through Credit Suisse First Boston Corporation
      ("CSFBC") specifically for use therein, it being understood and agreed
      that the only such information is that described as such in Section 7(b).

            2. The Company has been duly incorporated and is an existing
      corporation in good standing under the laws of the State of Virginia, with
      power and authority (corporate and other) to own its properties and
      conduct its business as described in the Offering Document; and the
      Company is duly qualified to do business as a foreign corporation in good
      standing in all other jurisdictions in which its ownership or lease of
      property or the conduct of its business requires such qualification,
      except where the failure to so qualify or to be in good standing, singly
      or in the aggregate, would not result in a material adverse effect on the
      condition (financial or other), business, properties or results of
      operations of the Company and its subsidiaries taken as a whole (a
      "MATERIAL ADVERSE EFFECT") .

            3. Each subsidiary of the Company has been duly incorporated and is
      an existing corporation in good standing under the laws of the
      jurisdiction of its incorporation, with power and authority (corporate and
      other) to own its properties and conduct its business as described in the
      Offering Document; and each subsidiary of the Company is duly qualified to
      do business as a foreign corporation in good standing in all other
      jurisdictions in which its ownership or lease of property or the conduct
      of its business requires such qualification, except where the failure to
      so qualify or to be in good standing, singly or in the aggregate, would
      not result in a Material Adverse Effect; all of the issued and outstanding
      capital stock of each subsidiary of the Company has been duly authorized
      and validly issued and is fully paid and nonassessable; and the capital
      stock of each subsidiary owned by the Company, directly or through
      subsidiaries, is owned free from liens, encumbrances and defects, other
      than liens created pursuant to the Company's existing senior credit
      facility. Other than the Subsidiary Guarantors, the Company has no
      significant subsidiaries within the meaning of Rule 1-02(w) of Regulation
      S-X under the Securities Act.

            4. The Indenture has been duly authorized by the Company and the
      Subsidiary Guarantors; the Offered Securities have been duly authorized;
      and when the Offered Securities are delivered and paid for pursuant to
      this Agreement on the Closing Date (as defined below), the Indenture will
      have been duly executed and delivered, such Offered Securities will have
      been duly executed, authenticated, issued and delivered and the Indenture
      and such Offered Securities will constitute valid and legally binding
      obligations of the Company and the Subsidiary Guarantors, enforceable in
      accordance with their terms, except to the extent that enforcement thereof
      may be limited by (i) bankruptcy, insolvency, fraudulent transfer,
      reorganization, moratorium and similar laws of general applicability
      relating to or affecting creditors' rights generally and (ii) to general
      principles of equity (regardless of whether enforcement is considered in a
      proceeding in equity or at law); and the Offered Securities conform in all
      material respects to the description thereof contained in the Offering
      Document.


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<PAGE>

            5. Each of the Registration Rights Agreement and the Escrow
      Agreement has been duly authorized by the Company and the Subsidiary
      Guarantors, as appropriate, and, when executed and delivered by the
      parties thereto, will constitute a valid and legally binding obligation of
      the Company and the Subsidiary Guarantors, as appropriate, enforceable in
      accordance with its terms, except (A) to the extent that enforcement
      thereof may be limited by (i) bankruptcy, insolvency, fraudulent transfer,
      reorganization, moratorium and similar laws of general applicability
      relating to or affecting creditors' rights generally and (ii) to general
      principles of equity (regardless of whether enforcement is considered in a
      proceeding in equity or at law) and (B) with respect to the Registration
      Rights Agreement, any rights to indemnity and contribution may be limited
      by Federal and state securities laws and public policy considerations; and
      the Registration Rights Agreement and the Escrow Agreement conform in all
      material respects to the descriptions thereof contained in the Offering
      Document.

            6. Each of the Transaction Documents has been or will be duly
      authorized by the Company, Buffalo and the Subsidiary Guarantors , as
      appropriate, and will conform in all material respects to the description
      thereof in the Offering Document and, when executed and delivered by the
      parties thereto, will constitute a valid and binding obligation of the
      Company, Buffalo and the Subsidiary Guarantors, as appropriate,
      enforceable against the Company and the Subsidiary Guarantors, as
      appropriate, in accordance with its terms, except to the extent that
      enforcement thereof may be limited by (i) bankruptcy, insolvency,
      fraudulent transfer, reorganization, moratorium and similar laws of
      general applicability relating to or affecting creditors' rights generally
      and (ii) to general principles of equity (regardless of whether
      enforcement is considered in a proceeding in equity or at law). The
      Company will advise the Initial Purchasers of any material developments
      relating to the Transaction Documents and, within one business day of the
      Acquisition closing date, deliver to the Initial Purchasers a true and
      correct copy of the Transaction Documents in the form originally executed.

            7. Except as disclosed in the Offering Document, there are no
      contracts, agreements or understandings between the Company and any person
      that would give rise to a valid claim against the Company or any Initial
      Purchaser for a brokerage commission, finder's fee or other like payment
      in connection with the transaction contemplated by this Agreement.

            8. Except as set forth in the Offering Document and assuming the
      accuracy of the representations, warranties and agreements of the Initial
      Purchasers under Section 4 of this Agreement, no consent, approval,
      authorization, or order of, or filing with, any governmental agency or
      body or any court is required for the consummation of the transactions
      contemplated by this Agreement in connection with the issuance and sale of
      the Offered Securities by the Company.

            9. The execution, delivery and performance of the Operative
      Documents and the Transaction Documents, and the issuance and sale of the
      Offered Securities and compliance with the terms and provisions thereof by
      the Company, Buffalo and the Subsidiary Guarantors and, as appropriate,
      will not result in a breach or violation of any of the terms and
      provisions of, or constitute a default under, any statute, rule,
      regulation or order of any governmental agency or body or any court,
      domestic or foreign, having jurisdiction over the Company or any
      subsidiary of the Company or any of their properties, or any agreement or
      instrument to which the Company or any such subsidiary is a party or by
      which the Company or any such subsidiary is bound or to which any of the
      properties of the Company or any such subsidiary is subject, or the
      charter or by-laws of the Company or any such subsidiary, except for such
      breaches, violations or defaults that, singly or in the aggregate, would
      not result in a Material Adverse Effect; and the Company and the
      Subsidiary Guarantors have the necessary power and authority to authorize,
      issue and sell the Offered Securities and the guaranties thereof,
      respectively, as contemplated by this Agreement.

            10. To the knowledge of the Company and the Subsidiary Guarantors,
      the execution, delivery and performance by A&T and CIC, as appropriate, of
      the Transaction Documents and compliance with the terms and provisions
      thereof will not result in a breach or violation of any of the terms and
      provisions of, or constitute a default under, any statute, rule,
      regulation or order of any governmental agency or body or any court,
      domestic or foreign, having jurisdiction over A&T or CIC or any of their
      properties, or any agreement or instrument to which A&T or CIC is a party
      or by which A&T or CIC is bound or to which any of their properties is
      subject, or the charter or by-laws of A&T or CIC.


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<PAGE>

            11. This Agreement has been duly authorized, executed and delivered
      by the Company and the Subsidiary Guarantors.

            12. Except as disclosed in the Offering Document, the Company and
      its subsidiaries have good and marketable title to material properties and
      all other material real properties and assets owned by them, in each case
      free from liens, encumbrances and defects that would materially affect the
      value thereof or materially interfere with the use made or proposed to be
      made thereof by them; and except as disclosed in the Offering Document,
      the Company and its subsidiaries hold any material leased real or personal
      property under valid and enforceable leases with no exceptions that would
      materially interfere with the use made or proposed to be made thereof by
      them.

            13. The Company and its subsidiaries possess adequate certificates,
      authorities or permits issued by appropriate governmental agencies or
      bodies necessary to conduct the business now operated by them and have not
      received any notice of proceedings relating to the revocation or
      modification of any such certificate, authority or permit that
      individually or in the aggregate would reasonably be expected to have a
      Material Adverse Effect.

            14. No labor dispute with the employees of the Company or any
      subsidiary exists or, to the knowledge of the Company, is imminent that
      would reasonably be expected to have a Material Adverse Effect.

            15. Except as described in the Offering Document, the Company and
      its subsidiaries own, possess, have the right to use or can acquire on
      reasonable terms, adequate trademarks, trade names and other rights to
      inventions, know-how, patents, copyrights, confidential information and
      other intellectual property (collectively, "INTELLECTUAL PROPERTY RIGHTS")
      necessary to conduct the business now operated by them, or presently
      employed by them, and have not received any notice of infringement of or
      conflict with asserted rights of others with respect to any intellectual
      property rights that individually or in the aggregate would reasonably be
      expected to have a Material Adverse Effect.

            16. Except as disclosed in the Offering Document, to the knowledge
      of the Company, neither the Company nor any of its subsidiaries is in
      violation of any statute, any rule, regulation, decision or order of any
      governmental agency or body or any court, domestic or foreign, relating to
      the use, disposal or release of hazardous or toxic substances or relating
      to the protection or restoration of the environment or human exposure to
      hazardous or toxic substances (collectively, "ENVIRONMENTAL LAWS"), owns
      or operates any real property contaminated with any substance that is
      subject to any environmental laws, is liable for any off-site disposal or
      contamination pursuant to any environmental laws, or is subject to any
      claim relating to any environmental laws, which violation, contamination,
      liability or claim would individually or in the aggregate have a Material
      Adverse Effect; and the Company is not aware of any pending investigation
      which would reasonably be expected to lead to such a claim.

            17. Except as disclosed in the Offering Document, there are no
      pending actions, suits or proceedings against or affecting the Company,
      any of its subsidiaries or any of their respective properties that
      individually or in the aggregate would reasonably be expected to have a
      Material Adverse Effect, or would materially and adversely affect the
      ability of the Company, Buffalo or any Subsidiary Guarantor, as
      appropriate, to perform its obligations under the Operative Documents or
      the Transaction Documents, or which are otherwise material in the context
      of the sale of the Offered Securities; and no such actions, suits or
      proceedings are threatened or, to the Company's knowledge, contemplated.

            18. The financial statements included in the Offering Document
      present fairly the financial position of (i) the Company and its
      consolidated subsidiaries and (ii) to the knowledge of the Company, A&T
      and its consolidated subsidiaries, as of the dates shown and their results
      of operations and cash flows for the periods shown, and such financial
      statements have been prepared in conformity with the generally accepted
      accounting principles in the United States applied on a consistent basis;
      and the assumptions used in preparing the pro forma financial statements
      included in the Offering Document provide a reasonable basis for
      presenting the significant effects directly attributable to the
      transactions or events described therein, the related pro forma
      adjustments give appropriate effect to those assumptions and the pro forma
      columns therein reflect the proper application of those adjustments to the
      corresponding historical financial statement amounts.


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<PAGE>

            19. Except as disclosed in the Offering Document, since the date of
      the latest audited financial statements included in the Offering Document
      there has been no material adverse change, nor any development or event
      involving a prospective material adverse change, in the condition
      (financial or other), business, properties or results of operations of the
      Company and its subsidiaries taken as a whole, and, except as disclosed in
      or contemplated by the Offering Document, there has been no dividend or
      distribution of any kind declared, paid or made by the Company on any
      class of its capital stock.

            20. Neither the Company nor any Subsidiary Guarantor is an open-end
      investment company, unit investment trust or face-amount certificate
      company that is or is required to be registered under Section 8 of the
      United States Investment Company Act of 1940 (the "INVESTMENT COMPANY
      ACT"); and neither the Company nor any Subsidiary Guarantor is nor, after
      giving effect to the offering and sale of the Offered Securities and the
      application of the proceeds thereof as described in the Offering Document,
      will be an "investment company" as defined in the Investment Company Act.

            21. No securities of the same class (within the meaning of Rule
      144A(d)(3) under the Securities Act) as the Offered Securities or the
      guarantees of the Subsidiary Guarantors are listed on any national
      securities exchange registered under Section 6 of the United States
      Securities Exchange Act of 1934 ("EXCHANGE ACT") or quoted in a U.S.
      automated inter-dealer quotation system.

            22. Assuming the accuracy of the representations, warranties and
      agreements of the Initial Purchasers in Section 4 of this Agreement, the
      offer and sale of the Offered Securities in the manner contemplated by
      this Agreement will be exempt from the registration requirements of the
      Securities Act by reason of Section 4(2) thereof and Regulation S
      thereunder; and it is not necessary to qualify an indenture in respect of
      the Offered Securities under the United States Trust Indenture Act of
      1939, as amended (the "TRUST INDENTURE ACT").

            23. Neither the Company, nor any of its affiliates, nor any person
      acting on its or their behalf (i) has, within the six-month period prior
      to the date hereof, offered or sold in the United States or to any U.S.
      person (as such terms are defined in Regulation S under the Securities
      Act) the Offered Securities or any security of the same class or series as
      the Offered Securities or (ii) has offered or will offer or sell the
      Offered Securities (A) in the United States by means of any form of
      general solicitation or general advertising within the meaning of Rule
      502(c) under the Securities Act or (B) with respect to any such securities
      sold in reliance on Rule 903 of Regulation S under the Securities Act, by
      means of any directed selling efforts within the meaning of Rule 902(c) of
      Regulation S. The Company, its affiliates and any person acting on its or
      their behalf have complied and will comply with the offering restrictions
      requirement of Regulation S. The Company has not entered and will not
      enter into any contractual arrangement with respect to the distribution of
      the Offered Securities except for this Agreement.

            24. KPMG LLP, who have certified certain financial statements of the
      Company and A&T, whose reports appear in the Offering Document and who
      have delivered the letters referred to in Section 6(a) hereof, are
      independent certified public accountants with respect to the Company and
      its subsidiaries and, to the knowledge of the Company, of A&T, as required
      by the Securities Act and the Rules and Regulations thereunder.

      3. PURCHASE, SALE AND DELIVERY OF OFFERED SECURITIES. On the basis of the
representations, warranties and agreements herein contained, but subject to the
terms and conditions herein set forth, the Company agrees to sell to the Initial
Purchasers, and the Initial Purchasers agree to purchase from the Company, at a
purchase price of 97% of the principal amount thereof plus accrued interest from
May 11, 1999 to the Closing Date (as hereinafter defined), the principal amount
of Offered Securities set forth opposite the name of the several Initial
Purchasers in Schedule A hereto.

      The Company will deliver against payment of the purchase price the Offered
Securities in the form of one or more permanent global Securities in definitive
form (the "Global Securities") deposited with the Trustee as custodian for The
Depository Trust Company ("DTC") and registered in the name of Cede & Co., as
nominee for DTC. Interests in any permanent global Securities will be held only
in book-entry form through DTC, except in the limited circumstances described in
the Offering Document. Payment for the Offered Securities shall be made by the
Initial Purchasers in Federal (same day) funds by wire transfer to an account
maintained by the Escrow Agent at a bank acceptable to CSFBC in connection


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with a closing to be held at the office of Cravath, Swaine & Moore at 9:00 A.M.
(New York time), on May 11, 1999, or at such other time not later than seven
full business days thereafter as CSFBC and the Company determine, such time
being herein referred to as the "CLOSING DATE", against delivery to the Trustee
as custodian for DTC of the Global Securities representing all of the Offered
Securities. The Global Securities will be made available for checking at the
above office at least 24 hours prior to the Closing Date.

      4. REPRESENTATIONS BY INITIAL PURCHASERS; RESALE BY INITIAL PURCHASERS.

            1. Each Initial Purchaser severally represents and warrants to the
Company that it is an "accredited investor" within the meaning of Regulation D
under the Securities Act.

            2. Each Initial Purchaser severally acknowledges that the Offered
Securities have not been registered under the Securities Act and may not be
offered or sold within the United States or to, or for the account or benefit
of, U.S. persons except in accordance with Regulation S or pursuant to an
exemption from the registration requirements of the Securities Act. Each Initial
Purchaser severally represents and agrees that it has offered and sold the
Offered Securities, and will offer and sell the Offered Securities (i) as part
of its distribution at any time and (ii) otherwise until the later of the
commencement of the offering and the Closing Date, only in accordance with Rule
903 or Rule 144A under the Securities Act ("RULE 144A"). Accordingly, neither
such Initial Purchaser nor its affiliates, nor any persons acting on its or
their behalf, have engaged or will engage in any directed selling efforts with
respect to the Offered Securities, and such Initial Purchaser, its affiliates
and all persons acting on its or their behalf have complied and will comply with
the offering restrictions requirements of Regulation S.

            3. Each Initial Purchaser severally agrees that it and each of its
affiliates or anyone acting on its behalf will not enter into any contractual
arrangement with respect to the distribution of the Offered Securities except
for any such arrangements with the other Initial Purchasers or affiliates of the
other Initial Purchasers or with the prior written consent of the Company.

            4. Each Initial Purchaser severally agrees that it and each of its
affiliates will not offer or sell the Offered Securities by means of any form of
general solicitation or general advertising, within the meaning of Rule 502(c)
under the Securities Act, including, but not limited to (i) any advertisement,
article, notice or other communication published in any newspaper, magazine or
similar media or broadcast over television or radio, or (ii) any seminar or
meeting whose attendees have been invited by any general solicitation or general
advertising. Each Initial Purchaser severally agrees, with respect to resales to
be made in reliance on Rule 144A of any of the Offered Securities, to deliver
either with the confirmation of such resale or otherwise prior to settlement of
such resale a notice to the effect that the resale of such Offered Securities
has been made in reliance upon the exemption from the registration requirements
of the Securities Act provided by Rule 144A.

            5. Each Initial Purchaser severally represents and agrees that (i)
it has not offered or sold and prior to the date six months after the date of
issue of the Offered Securities will not offer or sell any Offered Securities to
persons in the United Kingdom except to persons whose ordinary activities
involve them in acquiring, holding, managing or disposing of investments (as
principal or agent) for the purposes of their businesses or otherwise in
circumstances which have not resulted and will not result in an offer to the
public in the United Kingdom within the meaning of the Public Offers of
Securities Regulations 1995; (ii) it has complied and will comply with all
applicable provisions of the Financial Services Act 1986 with respect to
anything done by it in relation to the Offered Securities in, from or otherwise
involving the United Kingdom; and (iii) it has only issued or passed on and will
only issue or pass on in the United Kingdom any document received by it in
connection with the issue of the Offered Securities to a person who is of a kind
described in Article 11(3) of the Financial Services Act 1986 (Investment
Advertisements) (Exemptions) Order 1996 or is a person to whom such document may
otherwise lawfully be issued or passed on.

      5. CERTAIN AGREEMENTS OF THE COMPANY. The Company agrees with the several
Initial Purchasers that:

            1. The Company will advise CSFBC promptly of any proposal to amend
      or supplement the Offering Document and will not effect such amendment or
      supplementation without CSFBC's consent, which consent shall not be
      unreasonably withheld. If, at any time prior to the completion of the
      resale of the Offered Securities by the Initial Purchasers, any event
      occurs as a result of which the Offering Document as then amended or
      supplemented would include an untrue


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      statement of a material fact or omit to state any material fact necessary
      in order to make the statements therein, in the light of the circumstances
      under which they were made, not misleading, the Company will promptly
      notify CSFBC of such event and will promptly prepare, at its own expense,
      an amendment or supplement which will correct such statement or omission.
      Neither CSFBC's consent to, nor the Initial Purchasers' delivery to
      offerees or investors of, any such amendment or supplement shall
      constitute a waiver of any of the conditions set forth in Section 6.

            2. The Company will furnish to CSFBC copies of the Offering Document
      and all amendments and supplements to such documents, in each case as soon
      as available and in such quantities as CSFBC requests, and the Company
      will furnish to CSFBC on the date hereof three copies of the Offering
      Document signed by a duly authorized officer of the Company, one of which
      will include the independent accountants' reports therein manually signed
      by such independent accountants. At any time when the Company is not
      subject to Section 13 or 15(d) of the Exchange Act, the Company will
      promptly furnish or cause to be furnished to CSFBC (and, upon request, to
      each of the other Initial Purchasers) and, upon request of holders and
      prospective Initial Purchasers of the Offered Securities, to such holders
      and purchasers, copies of the information required to be delivered to
      holders and prospective purchasers of the Offered Securities pursuant to
      Rule 144A(d)(4) under the Securities Act (or any successor provision
      thereto) to the extent necessary to permit compliance with Rule 144A in
      connection with resales by such holders of the Offered Securities. The
      Company will pay the expenses of printing and distributing to the Initial
      Purchasers all such documents.

            3. The Company will use its best efforts, in cooperation with the
      Initial Purchasers, to arrange for the qualification of the Offered
      Securities for sale and the determination of their eligibility for
      investment under the laws of such jurisdictions in the United States and
      Canada as CSFBC designates and will continue such qualifications in effect
      so long as required for the resale of the Offered Securities by the
      Initial Purchasers, provided that the Company will not be required to
      qualify as a foreign corporation or to file a general consent to service
      of process in any such state.

            4. During the period of five years hereafter, the Company will
      furnish to CSFBC (and upon request, to each of the other Initial
      Purchasers), as soon as practicable after the end of each fiscal year, a
      copy of its annual report to stockholders for such year, if any; and the
      Company will furnish to CSFBC (and upon request, to each of the other
      Initial Purchasers) (i) as soon as available, a copy of each description
      of reports, notices or communications sent to securityholders or, if
      applicable, filed with foreign regulators or securities exchanges, and
      (ii) from time to time, such other information concerning the Company as
      CSFBC may reasonably request.

            5. During the period of two years after the Closing Date, the
      Company will, upon request, furnish to CSFBC (and upon request, to each of
      the other Initial Purchasers) and any holder of Offered Securities a copy
      of the restrictions on transfer applicable to the Offered Securities.

            6. During the period of two years after the Closing Date, the
      Company will not, and will not permit any of its affiliates (as defined in
      Rule 144 under the Securities Act) to, resell any of the Offered
      Securities that have been reacquired by any of them.

            7. During the period of two years after the Closing Date, the
      Company will not be or become, an open-end investment company, unit
      investment trust or face-amount certificate company that is or is required
      to be registered under Section 8 of the Investment Company Act.

            8. The Company will pay all expenses incidental to the performance
      of its obligations under this Agreement, the Indenture and the Escrow
      Agreement including (i) all expenses in connection with the execution,
      issue, authentication, packaging and initial delivery of the Offered
      Securities, the preparation and printing of this Agreement, the Offered
      Securities, the Offering Document and amendments and supplements thereto,
      the Indenture, the Escrow Agreement and any other document relating to the
      issuance, offer, sale and delivery of the Offered Securities; (ii) the
      cost of qualifying the Offered Securities for trading in The PortalSM
      Market ("PORTAL") and any expenses incidental thereto; (iii) the cost of
      any advertising approved by the Company in connection with the issue of
      the Offered Securities; (iv) for any expenses (including fees and
      disbursements of counsel) incurred in connection with qualification of the
      Offered Securities for sale under the laws of such jurisdictions in the
      United States and Canada as CSFBC in accordance with Section 5(c) hereof
      designates and the printing of memoranda relating thereto; (v) for any


                                       7
<PAGE>

      fees charged by investment rating agencies for the rating of the
      Securities; (vi) for expenses incurred in distributing preliminary
      offering circulars and the Offering Document (including any amendments and
      supplements thereto) to the Initial Purchasers and (vii) the fees and
      expenses of the Trustee, the Escrow Agent and their professional advisors.
      The Company will also pay or reimburse the Initial Purchasers (to the
      extent incurred by them) for all travel expenses of the Company's officers
      and employees and any other expenses of the Company in connection with
      attending or hosting meetings with prospective purchasers of the Offered
      Securities from the Initial Purchasers.

            9. In connection with the offering, until CSFBC shall have notified
      the Company and the other Initial Purchasers of the completion of the
      resale of the Offered Securities, neither the Company nor any of its
      affiliates has or will, either alone or with one or more other persons,
      bid for or purchase for any account in which it or any of its affiliates
      has a beneficial interest any Offered Securities or attempt to induce any
      person to purchase any Offered Securities; and neither it nor any of its
      affiliates will make bids or purchases for the purpose of creating actual,
      or apparent, active trading in, or of raising the price of, the Offered
      Securities.

            10. For a period of 180 days after the date of the initial offering
      of the Offered Securities by the Initial Purchasers, the Company will not
      offer, sell, contract to sell, pledge or otherwise dispose of, directly or
      indirectly, any United States dollar-denominated debt securities issued or
      guaranteed by the Company and having a maturity of more than one year from
      the date of issue or publicly disclose the intention to make any such
      offer, sale, pledge or disposition, without the prior written consent of
      CSFBC. The Company will not at any time offer, sell, contract to sell,
      pledge or otherwise dispose of, directly or indirectly, any securities
      under circumstances where such offer, sale, pledge, contract or
      disposition would cause the exemption afforded by Section 4(2) of the
      Securities Act or the safe harbor of Regulation S thereunder to cease to
      be applicable to the offer and sale of the Offered Securities.

            11. The Company will use its best efforts to cause the Offered
      Securities to become eligible for PORTAL.

      6. CONDITIONS OF THE OBLIGATION OF THE INITIAL PURCHASERS. The obligation
of the several Initial Purchasers to purchase and pay for the Offered Securities
will be subject to the accuracy of the representations and warranties on the
part of the Company herein, to the accuracy of the statements of officers of the
Company made pursuant to the provisions hereof, to the performance by the
Company of its obligations hereunder and to the following additional conditions
precedent:

            1. The Initial Purchasers shall have received a letter, dated the
      date of this Agreement, of KPMG LLP, independent auditors for the Issuer
      and A&T, substantially in the form of Exhibit B hereto and acceptable to
      the Initial Purchasers.

            2. Subsequent to the execution and delivery of this Agreement, there
      shall not have occurred (i) a change in U.S. or international financial,
      political or economic conditions or currency exchange rates or exchange
      controls as would, in the judgment of CSFBC, be likely to prejudice
      materially the success of the proposed issue, sale or distribution of the
      Offered Securities, whether in the primary market or in respect of
      dealings in the secondary market, or (ii) (A) any change, or any
      development or event involving a prospective change, in the condition
      (financial or other), business, properties or results of operations of the
      Company and its subsidiaries, taken as one enterprise, which, in the
      judgment of CSFBC, is material and adverse and makes it impractical or
      inadvisable to proceed with completion of the offering or the sale of and
      payment for the Offered Securities; (B) any downgrading in the rating of
      any debt securities of the Company by any "nationally recognized
      statistical rating organization" (as defined for purposes of Rule 436(g)
      under the Securities Act), or any public announcement that any such
      organization has under surveillance or review its rating of any debt
      securities of the Company (other than an announcement with positive
      implications of a possible upgrading, and no implication of a possible
      downgrading, of such rating); (C) any material suspension or material
      limitation of trading in securities generally on the New York Stock
      Exchange, or any setting of minimum prices for trading on such exchange,
      or any suspension of trading of any securities of the Company on any
      exchange or in the over-the-counter market; (D) any banking moratorium
      declared by U.S. Federal or New York authorities; or (E) any outbreak or
      escalation of major hostilities in which the United States is involved,
      any declaration of war by Congress or any other substantial national or
      international calamity or emergency if, in the judgment of CSFBC, the
      effect of any such outbreak, escalation, declaration, calamity or
      emergency makes it impractical or


                                       8
<PAGE>

      inadvisable to proceed with completion of the offering or sale of and
      payment for the Offered Securities.

            3. The Initial Purchasers shall have received opinions, dated the
      Closing Date, of Curtis L. Schehr, Esq., general counsel of the Company,
      that:

                  (i) Based solely on certificates of public officials in the
            respective jurisdictions, each of the Company and the Subsidiary
            Guarantors is duly incorporated and is an existing corporation in
            good standing under the laws of the State of Virginia and is duly
            qualified to do business as a foreign corporation in good standing
            in all other jurisdictions in which its ownership or lease of
            property or the conduct of its business requires such qualification
            and to such counsels' knowledge, it is not necessary for the Company
            and the Subsidiary Guarantors to be qualified to do business as a
            foreign corporation in any other jurisdictions;

                  (ii) To the knowledge of such counsel, the execution, delivery
            and performance of the Operative Documents and the Transaction
            Documents, and the issuance and sale of the Offered Securities and
            compliance with the terms and provisions thereof by the Company,
            Buffalo and the Subsidiary Guarantors, as appropriate, will not
            result in a breach or violation of any of the terms and provisions
            of, or constitute a default under, any statute, rule, regulation or
            order of any governmental agency or body or any court having
            jurisdiction over the Company, Buffalo or any Subsidiary Guarantor
            or any of their properties, or any agreement or instrument to which
            the Company, Buffalo or any Subsidiary Guarantor is a party or by
            which the Company, Buffalo or any Subsidiary Guarantor is bound or
            to which any of the properties of the Company, Buffalo or any
            Subsidiary Guarantor is subject, or the charter or by-laws of the
            Company, Buffalo or any Subsidiary Guarantor; and

                  (iii) To the knowledge of such counsel, and except as
            described in the Offering Document, there are no pending actions,
            suits or proceedings against or affecting the Company, any of its
            subsidiaries or any of their respective properties that individually
            or in the aggregate would reasonably be expected to have a Material
            Adverse Effect, or would materially and adversely affect the ability
            of the Company, Buffalo or any Subsidiary Guarantor, as appropriate,
            to perform its obligations under the Operative Documents or the
            Transaction Documents; and to the knowledge of such counsel, no such
            actions, suits or proceedings are threatened or contemplated.

            4. The Initial Purchasers shall have received opinions, dated the
      Closing Date, of McGuire Woods Battle & Boothe LLP, Virginia counsel to
      the Company and the Subsidiary Guarantors, that:

                  (i) Each of the Company and the Subsidiary Guarantors has been
            duly incorporated and is an existing corporation in good standing
            under the laws of the applicable jurisdiction, with corporate power
            and authority to own its properties and conduct its business as
            described in the Offering Document; and the Company has the
            necessary corporate power to authorize, issue and sell, and each
            Subsidiary Guarantor has the necessary corporate power to guarantee,
            the Offered Securities as contemplated by this Agreement;

                  (ii) Each of the Operative Documents has been duly authorized
            by the Company and the Subsidiary Guarantors, as appropriate; and

                  (iii) The Merger Agreement has been duly authorized by the
            Company.

            5. The Initial Purchasers shall have received opinions, dated the
      Closing Date, of Paul, Weiss, Rifkind, Wharton & Garrison, counsel for the
      Company and the Subsidiary Guarantors, that:

                  (i) Based solely on certificates of public officials in the
            respective jurisdictions delivered to such counsel by the Company,
            each of the Company and each Subsidiary Guarantor has been duly
            incorporated and is an existing corporation in good standing


                                       9
<PAGE>

            under the laws of the State of Virginia, and each is duly qualified
            to do business in the jurisdictions listed on schedule attached to
            such opinion;

                  (ii) The Indenture has been duly executed and delivered by the
            Company and the Subsidiary Guarantors; the Offered Securities have
            been duly executed, issued and delivered by the Company and conform
            in all material respects to the description thereof contained in the
            Offering Document under the caption "Description of the Notes"; and,
            assuming due power and authorization by the Company and the
            Subsidiary Guarantors, the Indenture and the Offered Securities will
            constitute valid and legally binding obligations of the Company and
            the Subsidiary Guarantors, enforceable against the Company and the
            Subsidiary Guarantors in accordance with their terms, except to the
            extent that enforcement thereof may be limited by (i) bankruptcy,
            insolvency, fraudulent conveyance or transfer, reorganization,
            moratorium and similar laws of general applicability relating to or
            affecting creditors' rights generally and (ii) to general principles
            of equity (regardless of whether enforcement is considered in a
            proceeding in equity or at law);

                  (iii) Each of the Registration Rights Agreement and the Escrow
            Agreement has been duly executed and delivered by the Company and
            the Subsidiary Guarantors, as appropriate; and each of the
            Registration Rights Agreement and the Escrow Agreement conforms in
            all material respects to the descriptions thereof contained in the
            Offering Document under the caption "Description of the Notes" and,
            assuming due power and authorization by the Company and the
            Subsidiary Guarantors, constitutes a valid and legally binding
            obligation of the Company and the Subsidiary Guarantors, as
            appropriate, enforceable in accordance with its terms, except (A) to
            the extent that enforcement thereof may be limited by (i)
            bankruptcy, insolvency, fraudulent transfer, reorganization,
            moratorium and similar laws of general applicability relating to or
            affecting creditors' rights generally and (ii) general principles of
            equity (regardless of whether enforceability is considered in
            proceeding in equity or at law) and (B) with respect to the
            Registration Rights Agreements, any rights to indemnity and
            contribution may be limited by Federal and state securities laws and
            public policy considerations;

                  (iv) This agreement has been duly executed and delivered by
            the Company and the Subsidiary Guarantors;

                  (v) Neither the Company nor any Subsidiary Guarantor is nor,
            after giving effect to the offering and sale of the Offered
            Securities and the application of the proceeds thereof as described
            in the Offering Document, will be required to be registered as an
            investment company under the Investment Company Act of 1940;

                  (vi) No consent, approval, authorization or order of, or
            filing with, any executive, legislative, judicial, administrative or
            regulatory body of the United States of America which has not been
            obtained, taken or made under the laws, rules and regulations of the
            United States of America which in such counsel's experience are
            normally applicable to the transactions of the type contemplated by
            this Agreement (the "Applicable Law") is required for the
            consummation of the transactions contemplated by this Agreement, the
            Escrow Agreement, the Registration Rights Agreement or the Indenture
            for the issuance or sale of the Offered Securities by the Company,
            except such as may be required under state securities laws;

                  (vii) The execution, delivery and performance of the Operative
            Documents, and the issuance and sale of the Offered Securities and
            compliance with the terms and provisions thereof by the Company and
            its Subsidiary Guarantors, as appropriate, will not (i) violate
            Applicable Law, except where the violation would not have a Material
            Adverse Effect, (ii) breach or result in a default under any
            agreement or instrument listed in Schedule C hereto, or (iii) result
            in a violation of the charter or by-laws of the Company or any
            Subsidiary Guarantor certified by the Company as in effect on the
            date of the opinion;

                  (viii) The description of the Merger Agreement contained in
            the Offering Document fairly summarize the terms of the Merger
            Agreement in all material respects;

                  (ix) Assuming the accuracy of the representations, warranties
            and agreements of the Company (other than the representation and
            warranty in Section 2(v) of this


                                       10
<PAGE>

            Agreement), the Subsidiary Guarantors and the Initial Purchasers
            contained in this Agreement, (i) the offer, sale and delivery of the
            Offered Securities by the Company to the Initial Purchasers pursuant
            to this Agreement and (ii) the resales of the Offered Securities by
            the Initial Purchasers in the manner contemplated by the Offering
            Document and this Agreement are exempt from the registration
            requirements of the Securities Act and it is not necessary to
            qualify an indenture in respect thereof under the Trust Indenture
            Act; and

                  (x) Such counsel has participated in the preparation of the
            Offering Document and, although it has not undertaken to investigate
            or verify independently, and does not assume responsibility for, the
            accuracy or completeness of the statements contained therein (other
            than as explicitly stated in paragraphs (ii) and (iii) above), based
            upon such participation, no facts have come to its attention to lead
            it to believe that the Offering Document or any amendment or
            supplement (except for the financial statements, financial statement
            schedules and other financial or statistical data included or
            incorporated by reference in or omitted from those documents, as to
            which it expresses no such belief), at the time the Offering
            Document was issued or on the date of the opinion, included or
            includes an untrue statement of a material fact or omitted or omits
            to state a material fact necessary in order to make the statements
            therein, in the light of the circumstances under which they were
            made, not misleading.

            6. The Initial Purchasers shall have received from Cravath, Swaine &
      Moore, counsel for the Initial Purchasers, such opinion or opinions, dated
      the Closing Date, with respect to the incorporation of the Company, the
      validity of the Offered Securities, the Offering Document, the exemption
      from registration for the offer and sale of the Offered Securities by the
      Company to the several Initial Purchasers and the resales by the several
      Initial Purchasers as contemplated hereby and other related matters as
      CSFBC may require, and the Company shall have furnished to such counsel
      such documents as they request for the purpose of enabling them to pass
      upon such matters. In rendering such opinion, Cravath, Swaine & Moore may
      rely as to the incorporation of the Company and all other matters governed
      by Virginia law upon the opinion of McGuire Woods Battle & Boothe LLP
      referred to above.

            7. The Initial Purchasers shall have received a certificate, dated
      the Closing Date, of the President or any Vice President and a principal
      financial or accounting officer of the Company and the Subsidiary
      Guarantors in which such officers, to the best of their knowledge after
      reasonable investigation, shall state that the representations and
      warranties of the Company in this Agreement are true and correct, that the
      Company has complied with all agreements and satisfied all conditions on
      its part to be performed or satisfied hereunder at or prior to the Closing
      Date, and that, subsequent to the date of the most recent financial
      statements in the Offering Document, there has been no material adverse
      change, nor any development or event involving a prospective material
      adverse change, in the condition (financial or other), business,
      properties or results of operations of the Company and its subsidiaries
      taken as one enterprise except as set forth in or contemplated by the
      Offering Document or as described in such certificate.

            8. The Initial Purchasers shall have received a letter, dated the
      Closing Date, of KPMG LLP which meets the requirements of subsection (a)
      of this Section, except that the specified date referred to in such
      subsection will be a date not more than three business days prior to the
      Closing Date for the purposes of this subsection.

            9. The Company shall execute and deliver the Registration Rights
      Agreement and the Escrow Agreement and deposit the amounts required in the
      Escrow Agreement into an escrow account, pursuant to the terms of the
      Escrow Agreement.

            10. The Initial Purchasers shall have received the necessary waivers
      with respect to any default under its existing senior credit facility.

      The Company will furnish the Initial Purchasers with such conformed copies
of such opinions, certificates, letters and documents as the Initial Purchasers
reasonably request. CSFBC may in its sole discretion waive on behalf of the
Initial Purchasers compliance with any conditions to the obligations of the
Initial Purchasers hereunder.

      7. INDEMNIFICATION AND CONTRIBUTION. (a) The Company and the Subsidiary
Guarantors will jointly and severally indemnify and hold harmless each Initial
Purchaser, its directors and officers and each


                                       11
<PAGE>

person, if any, who controls such Initial Purchaser within the meaning of
Section 15 of the Securities Act against any losses, claims, damages or
liabilities, joint or several, to which such Initial Purchaser may become
subject, under the Securities Act or the Exchange Act or otherwise, insofar as
such losses, claims, damages or liabilities (or actions in respect thereof)
arise out of or are based upon any breach of any of the representations and
warranties of the Company contained herein or any untrue statement or alleged
untrue statement of any material fact contained in the Offering Document, or any
amendment or supplement thereto, or arise out of or are based upon the omission
or alleged omission to state therein a material fact necessary in order to make
the statements therein, in the light of the circumstances under which they were
made, not misleading, including any losses, claims, damages or liabilities
arising out of or based upon the Company's failure to perform its obligations
under Section 5(a) of this Agreement, and will reimburse each Initial Purchaser
for any legal or other expenses reasonably incurred by such Initial Purchaser in
connection with investigating or defending any such loss, claim, damage,
liability or action as such expenses are incurred; PROVIDED, HOWEVER, that the
Company will not be liable in any such case to the extent that any such loss,
claim, damage or liability arises out of or is based upon an untrue statement or
alleged untrue statement in or omission or alleged omission from any of such
documents in reliance upon and in conformity with written information furnished
to the Company by any Initial Purchaser through CSFBC specifically for use
therein, it being understood and agreed that the only such information consists
of the information described as such in subsection (b) below; and PROVIDED
FURTHER, HOWEVER, that the foregoing indemnity with respect to the preliminary
offering circular shall not inure to the benefit of the Initial Purchaser from
whom the person asserting any such losses, claims, damages, liabilities or
actions in respect thereof purchased Offered Securities to the extent that such
losses, claims, damages, liabilities or actions in respect thereof of such
Initial Purchaser result from a fact that such Initial Purchaser sold Offered
Securities to a person in an initial resale to whom there was not sent or given,
at or prior to the written confirmation of the sale of such Offered Securities,
a copy of the offering circular (as amended or supplemented), if the Company had
previously furnished a copy of such amendments or supplements to such Initial
Purchaser, and the losses, claims, damages, liabilities or actions in respect
thereof of such Initial Purchaser result from an untrue statement or omission of
a material fact contained in the preliminary offering circular, which was
corrected in the offering circular.

      (b) Each Initial Purchaser will severally and not jointly indemnify and
hold harmless the Company, the Subsidiary Guarantors, their directors and
officers and each person, if any, who controls each of the Company or any
Subsidiary Guarantor within the meaning of Section 15 of the Securities Act,
against any losses, claims, damages or liabilities to which the Company may
become subject, under the Securities Act or the Exchange Act or otherwise,
insofar as such losses, claims, damages or liabilities (or actions in respect
thereof) arise out of or are based upon any untrue statement or alleged untrue
statement of any material fact contained in the Offering Document, or any
amendment or supplement thereto, or arise out of or are based upon the omission
or the alleged omission to state therein a material fact necessary in order to
make the statements therein, in the light of the circumstances under which they
were made, not misleading, in each case to the extent, but only to the extent,
that such untrue statement or alleged untrue statement or omission or alleged
omission was made in reliance upon and in conformity with written information
furnished to the Company by such Initial Purchaser through CSFBC specifically
for use therein, and will reimburse any legal or other expenses reasonably
incurred by the Company or any Subsidiary Guarantor in connection with
investigating or defending any such loss, claim, damage, liability or action as
such expenses are incurred, it being understood and agreed that the only such
information furnished by any Initial Purchaser consists of the following
information in the Offering Document: the information contained in the third
paragraph, the second sentence of the sixth paragraph, the seventh paragraph and
the last paragraph of "Plan of Distribution".

      (c) Promptly after receipt by an indemnified party under this Section 7 of
notice of the commencement of any action, such indemnified party will, if a
claim in respect thereof is to be made against the indemnifying party under
subsection (a) or (b) above, notify the indemnifying party of the commencement
thereof; but the omission so to notify the indemnifying party (i) will not
relieve it from any liability under subsection (a) or (b) above unless and to
the extent it did not otherwise learn of such action and such failure results in
the forfeiture by the indemnifying party of substantial rights and defenses and
(ii) will not, in any event, relieve the indemnifying party from any liability
which it may have to any indemnified party otherwise than under subsection (a)
or (b) above. In case any such action is brought against any indemnified party
and it notifies the indemnifying party of the commencement thereof, the
indemnifying party will be entitled to participate therein and, to the extent
that it may wish, jointly with any other indemnifying party similarly notified,
to assume the defense thereof, with counsel reasonably satisfactory to such
indemnified party (who shall not, except with the consent of the indemnified
party, be counsel to the indemnifying party), and after notice from the
indemnifying party to such indemnified party of its election so to assume the
defense thereof, the indemnifying party will not be liable to such indemnified
party under this Section 7 for any legal or other expenses subsequently incurred
by such


                                       12
<PAGE>

indemnified party in connection with the defense thereof other than reasonable
costs of investigation. No indemnifying party shall, without the prior written
consent of the indemnified party, effect any settlement of any pending or
threatened action in respect of which any indemnified party is or could have
been a party and indemnity could have been sought hereunder by such indemnified
party unless such settlement includes an unconditional release of such
indemnified party from all liability on any claims that are the subject matter
of such action and does not include a statement as to any admission of fault,
culpability or failure to act by or on behalf of any Indemnified Party.

      (d) If the indemnification provided for in this Section 7 is unavailable
or insufficient to hold harmless an indemnified party under subsection (a) or
(b) above, then each indemnifying party shall contribute to the amount paid or
payable by such indemnified party as a result of the losses, claims, damages or
liabilities referred to in subsection (a) or (b) above (i) in such proportion as
is appropriate to reflect the relative benefits received by the Company and the
Subsidiary Guarantors on the one hand and the Initial Purchasers on the other
from the offering of the Offered Securities or (ii) if the allocation provided
by clause (i) above is not permitted by applicable law, in such proportion as is
appropriate to reflect not only the relative benefits referred to in clause (i)
above but also the relative fault of the Company and the Subsidiary Guarantors
on the one hand and the Initial Purchasers on the other in connection with the
statements or omissions which resulted in such losses, claims, damages or
liabilities as well as any other relevant equitable considerations. The relative
benefits received by the Company and the Subsidiary Guarantors on the one hand
and the Initial Purchasers on the other shall be deemed to be in the same
proportion as the total net proceeds from the offering (before deducting
expenses) received by the Company bear to the total discounts and commissions
received by the Initial Purchasers from the Company under this Agreement. The
relative fault shall be determined by reference to, among other things, whether
the untrue or alleged untrue statement of a material fact or the omission or
alleged omission to state a material fact relates to information supplied by the
Company or any Subsidiary Guarantors or the Initial Purchasers and the parties'
relative intent, knowledge, access to information and opportunity to correct or
prevent such untrue statement or omission. The amount paid by an indemnified
party as a result of the losses, claims, damages or liabilities referred to in
the first sentence of this subsection (d) shall be deemed to include any legal
or other expenses reasonably incurred by such indemnified party in connection
with investigating or defending any action or claim which is the subject of this
subsection (d). Notwithstanding the provisions of this subsection (d), no
Initial Purchaser shall be required to contribute any amount in excess of the
amount by which the total price at which the Offered Securities purchased by it
were resold exceeds the amount of any damages which such Initial Purchaser has
otherwise been required to pay by reason of such untrue or alleged untrue
statement or omission or alleged omission. The Initial Purchasers' obligations
in this subsection (d) to contribute are several in proportion to their
respective purchase obligations and not joint.

      (e) The obligations of the Company and the Subsidiary Guarantors under
this Section 7 shall be in addition to any liability which the Company and the
Subsidiary Guarantors may otherwise have and shall extend, upon the same terms
and conditions, to each person, if any, who controls any Initial Purchaser
within the meaning of the Securities Act or the Exchange Act; and the
obligations of the Initial Purchasers under this Section 7 shall be in addition
to any liability which the respective Initial Purchasers may otherwise have and
shall extend, upon the same terms and conditions, to each person, if any, who
controls the Company within the meaning of the Securities Act or the Exchange
Act.

      8. DEFAULT OF INITIAL PURCHASERS. If any Initial Purchaser or Initial
Purchasers default in their obligations to purchase Offered Securities hereunder
and the aggregate principal amount of Offered Securities that such defaulting
Initial Purchaser or Initial Purchasers agreed but failed to purchase does not
exceed 10% of the total principal amount of Offered Securities, CSFBC may make
arrangements satisfactory to the Company for the purchase of such Offered
Securities by other persons, including any of the Initial Purchasers, but if no
such arrangements are made by the Closing Date, the non-defaulting Initial
Purchasers shall be obligated severally, in proportion to their respective
commitments hereunder, to purchase the Offered Securities that such defaulting
Initial Purchasers agreed but failed to purchase. If any Initial Purchaser or
Initial Purchasers so default and the aggregate principal amount of Offered
Securities with respect to which such default or defaults occur exceeds 10% of
the total principal amount of shares of Offered Securities and arrangements
satisfactory to CSFBC and the Company for the purchase of such Offered
Securities by other persons are not made within 36 hours after such default,
this Agreement will terminate without liability on the part of any
non-defaulting Initial Purchaser or the Company, except as provided in Section
9. As used in this Agreement, the term "Initial Purchaser" includes any person
substituted for an Initial Purchaser under this Section. Nothing herein will
relieve a defaulting Initial Purchaser from liability for its default.


                                       13
<PAGE>

      9. SURVIVAL OF CERTAIN REPRESENTATIONS AND OBLIGATIONS. The respective
indemnities, agreements, representations, warranties and other statements of the
Company or its officers and of the several Initial Purchasers set forth in or
made pursuant to this Agreement will remain in full force and effect, regardless
of any investigation, or statement as to the results thereof, made by or on
behalf of any Initial Purchaser, the Company or any of their respective
representatives, officers or directors or any controlling person, and will
survive delivery of and payment for the Offered Securities. If this Agreement is
terminated pursuant to Section 8 or if for any reason the purchase of the
Offered Securities by the Initial Purchasers is not consummated, the Company
shall remain responsible for the expenses to be paid or reimbursed by it
pursuant to Section 5 and the respective obligations of the Company and the
Initial Purchasers pursuant to Section 7 shall remain in effect. If the purchase
of the Offered Securities by the Initial Purchasers is not consummated for any
reason other than solely because of the occurrence of any event specified in
clause (C), (D) or (E) of Section 6(b)(ii), the Company will reimburse the
Initial Purchasers for all out-of-pocket expenses (including fees and
disbursements of counsel) reasonably incurred by them in connection with the
offering of the Offered Securities.

      10. NOTICES. All communications hereunder will be in writing and, if sent
to the Initial Purchasers will be mailed, delivered or telegraphed and confirmed
to the Initial Purchasers c/o Credit Suisse First Boston Corporation, Eleven
Madison Avenue, New York, N.Y. 10010-3629, Attention: Investment Banking
Department--Transactions Advisory Group, or, if sent to the Company, will be
mailed, delivered or telegraphed and confirmed to it at 3211 Jermantown Road,
Suite 700, Fairfax, VA 22030-2801, Attention: General Counsel, with a copy to
Paul, Weiss, Rifkind, Wharton & Garrison, 1285 Avenue of the Americas, New York,
NY 10019, Attention: Carl L. Reisner; PROVIDED, HOWEVER, that any notice to an
Initial Purchaser pursuant to Section 7 will be mailed, delivered or telegraphed
and confirmed to such Initial Purchaser.

      11. SUCCESSORS. This Agreement will inure to the benefit of and be binding
upon the parties hereto and their respective successors and the controlling
persons referred to in Section 7, and no other person will have any right or
obligation hereunder, except that holders of Offered Securities shall be
entitled to enforce the agreements for their benefit contained in the second and
third sentences of Section 5(b) hereof against the Company as if such holders
were parties thereto.

      12. COUNTERPARTS. This Agreement may be executed in any number of
counterparts, each of which shall be deemed to be an original, but all such
counterparts shall together constitute one and the same Agreement.

      13. APPLICABLE LAW. THIS AGREEMENT SHALL BE GOVERNED BY, AND CONSTRUED IN
ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK WITHOUT REGARD TO PRINCIPLES
OF CONFLICTS OF LAWS.

      The Company, the Subsidiary Guarantors and the Initial Purchasers hereby
submit to the non-exclusive jurisdiction of the Federal and state courts in the
Borough of Manhattan in The City of New York in any suit or proceeding arising
out of or relating to this Agreement or the transactions contemplated hereby.


                                       14
<PAGE>

      If the foregoing is in accordance with your understanding of our
agreement, kindly sign and return to the Company one of the counterparts hereof,
whereupon it will become a binding agreement between the Company, the Subsidiary
Guarantors and the several Initial Purchasers in accordance with its terms.

                                    Very truly yours,

                                    ANTEON CORPORATION,


                                    by
                                       -------------------------------------
                                       Name:
                                       Title:


                                    VECTOR DATA SYSTEMS, INC.,


                                    by
                                       -------------------------------------
                                       Name:
                                       Title:


                                    TECHMATICS, INC.,


                                    by
                                       -------------------------------------
                                       Name:
                                       Title:


The foregoing Purchase
Agreement is hereby confirmed
and accepted as of the date first
above written.

CREDIT SUISSE FIRST BOSTON CORPORATION
DEUTSCHE BANK SECURITIES INC.
LEGG MASON WOOD WALKER, INCORPORATED

Acting on behalf of itself and as the Representative of the several Initial
Purchasers.

by: CREDIT SUISSE FIRST BOSTON CORPORATION


    by
       -------------------------------------
       Name:
       Title:


                                       15
<PAGE>

                                   SCHEDULE A

                                                      Principal Amount of
Initial Purchaser                                     Offered Securities
-----------------                                     ------------------
Credit Suisse First Boston Corporation............        $ 80,000,000
Deutsche Bank Securities Inc.  ...................        $ 15,000,000

Legg Mason Wood Walker, Incorporated  ............        $  5,000,000
                  Total...........................
                                                         -------------

                                                         $ 100,000,000
                                                         =============


                                       16
<PAGE>

                                   SCHEDULE B

                           FORM OF KPMG COMFORT LETTER


                                       17
<PAGE>

                                   SCHEDULE C

                             AGREEMENTS/INSTRUMENTS

      1. Credit Agreement by and among Anteon Corporation and Vector Data
Systems, Inc., as Borrowers, and Mellon Bank, N.A., First Union Capital Markets
Group, Nationsbank, N.A. and Deutschebank AG, as Lenders, and Mellon Bank, N.A.,
as Agent, dated March 18, 1998, as amended by the Joinder Agreement and
Amendment No. 1 to Credit Agreement, dated as of May 29, 1998 and as further
amended by the Amendment No. 2 to Credit Agreement, dated as of November, 1998,
and as further amended by the Amendment No. 3 and Waiver, dated as of May 5,
1999.


                                       18
