
<PAGE>
 
                                                                     EXHIBIT 1.1





                                    ACC CORP.

                CLASS A COMMON STOCK (par value $0.015 per share)





                             UNDERWRITING AGREEMENT






















_____________ , 1996
<PAGE>
 
                                                            _____________ , 1996



Morgan Stanley & Co.
  Incorporated
Wheat, First Securities, Inc.
c/o Morgan Stanley & Co.
      Incorporated
    1585 Broadway
    New York, New York  10036


Ladies and Gentlemen:

          ACC Corp., a Delaware corporation (the "Company"), proposes to issue
and sell to the several Underwriters named in Schedule I hereto (the
"Underwriters"), 1,750,000 shares of Class A Common Stock (par value $0.015 per
share) of the Company (the "Firm Shares").

          The Company also proposes to issue and sell to the several
Underwriters not more than an additional 262,500 shares of its Class A Common
Stock (par value $0.015 per share) (the "Additional Shares") if and to the
extent that you shall have determined to exercise, on behalf of the
Underwriters, the right to purchase such shares of Class A Common Stock granted
to the Underwriters in Article II hereof. The Firm Shares and the Additional
Shares are hereinafter collectively referred to as the "Shares". The shares of
Class A Common Stock (par value $0.015 per share) of the Company to be
outstanding after giving effect to the sales contemplated hereby are hereinafter
referred to as the "Common Stock".

          The Company has filed with the Securities and Exchange Commission (the
"Commission") a registration statement, including a prospectus, relating to the
Shares. The registration statement, as amended at the time it becomes effective,
including the information (if any) deemed to be part of the registration
statement at the time of effectiveness pursuant to Rule 430A under the
Securities Act of 1933, as amended (the "Securities Act"), is hereinafter
referred to as the "Registration Statement"; and the prospectus in the form
first used to confirm sales of Shares is hereinafter referred to as the
"Prospectus". As used herein, the term "Registration Statement" shall include
all exhibits thereto and the terms "Registration Statement", "Prospectus" and
"preliminary prospectus" shall include all documents incorporated therein by
reference pursuant to Form S-3 under the Securities Act as of the date of the
Registration Statement, Prospectus or the preliminary prospectus, as the case
may be. The terms "supplement" and "amendment" or "amend" as used in this
Agreement shall include all documents subsequently filed by the Company with the
Commission pursuant to the Securities
<PAGE>
 
                                       2

Exchange Act of 1934, as amended (the "Exchange Act"), that are deemed to be
incorporated by reference in the Prospectus pursuant to Form S-3 under the
Securities Act. If the Company files a registration statement to register a
portion of the Shares and relies on Rule 462(b) for such registration statement
to become effective upon filing with the Commission (the "Rule 462(b)
Registration Statement"), then any reference to the "Registration Statement"
shall be deemed to refer to both the registration statement referred to above
(Commission File No. 333-01157) and the Rule 462(b) Registration Statement, in
each case as amended from time to time.


                                       I.

          The Company represents and warrants to each of the Underwriters that:

               (a) The Registration Statement has become effective; no stop
          order suspending the effectiveness of the Registration Statement is in
          effect, and no proceedings for such purpose are pending before or, to
          the Company's knowledge, threatened by the Commission.

               (b) (i) Each part of the Registration Statement, when such part
          became effective, did not contain and each such part, as amended or
          supplemented, if applicable, will not contain any untrue statement of
          a material fact or omit to state a material fact required to be stated
          therein or necessary to make the statements therein not misleading,
          (ii) the Registration Statement and the Prospectus comply and, as
          amended or supplemented, if applicable, will comply in all material
          respects with the Securities Act and the applicable rules and
          regulations of the Commission thereunder, (iii) each document filed or
          to be filed pursuant to the Exchange Act and incorporated by reference
          in the Prospectus complied or will comply when so filed in all
          material respects with the Exchange Act and the applicable rules and
          regulations of the Commission thereunder, and (iv) the Prospectus does
          not contain and, as amended or supplemented, if applicable, will not
          contain any untrue statement of a material fact or omit to state a
          material fact necessary to make the statements therein, in the light
          of the circumstances under which they were made, not misleading,
          except that the representations and warranties set forth in this
          paragraph (b) do not apply to statements or omissions in the
          Registration Statement or the Prospectus based upon information
          relating to any Underwriter furnished to the Company in writing by
          such Underwriter through you expressly for use therein.

               (c) The Company has been duly incorporated, is validly existing
          as a corporation in good standing under the laws of the State of
          Delaware, has the corporate power and authority to own its property
          and to conduct its business as described in the Prospectus and is duly
          qualified to transact business and is in good standing in each
          jurisdiction in which the conduct of its business or its ownership or
          leasing of property
<PAGE>
 
                                        3

          requires such qualification, except to the extent that the failure to
          be so qualified or be in good standing would not have a material
          adverse effect on the Company and its subsidiaries, taken as a whole.

               (d) Each of the Company's significant subsidiaries (as such term
          is defined in Rule 1-02(w) of Regulation S-X under the Securities Act)
          and ACC National Telecom Corp. has been duly incorporated, is validly
          existing as a corporation in good standing under the laws of the
          jurisdiction of its incorporation, has the corporate power and
          authority to own its property and to conduct its business as described
          in the Prospectus and is duly qualified to transact business and is in
          good standing in each jurisdiction in which the conduct of its
          business or its ownership or leasing of property requires such
          qualification, except to the extent that the failure to be so
          qualified or be in good standing would not have a material adverse
          effect on the Company and its subsidiaries, taken as a whole. Neither
          the Company nor any of its subsidiaries conducts any business in the
          District of Columbia, Alaska, Arizona, Hawaii, Kentucky or Vermont.

               (e) The authorized capital stock of the Company conforms as to
          legal matters to the description thereof contained in the Prospectus.

               (f) The shares of Common Stock outstanding prior to the issuance
          of the Shares have been duly authorized and are validly issued, fully
          paid and non-assessable.

               (g) The Shares have been duly authorized and, when issued and
          delivered in accordance with the terms of this Agreement, will be
          validly issued, fully paid and non-assessable, and the issuance of
          such Shares will not be subject to any preemptive or similar rights to
          which the Company is subject.

               (h) This Agreement has been duly authorized, executed and
          delivered by the Company.

               (i) The execution and delivery by the Company of, and the
          performance by the Company of its obligations under, this Agreement
          will not contravene any provision of applicable law or the certificate
          of incorporation or by-laws of the Company or any agreement or other
          instrument binding upon the Company or any of its subsidiaries, or any
          judgment, order or decree of any governmental body, agency or court
          having jurisdiction over the Company or any subsidiary, and no
          consent, approval, authorization or order of or qualification with any
          governmental body or agency is required for the performance by the
          Company of its obligations under this Agreement, except such as may be
          required by the securities or Blue Sky laws of the various states of
          the United States of America or of any jurisdiction outside the United
          States of America in connection with the offer and sale of the Shares.
<PAGE>
 
                                        4

               (j) There has not occurred any material adverse change, or any
          development involving a prospective material adverse change, in the
          condition, financial or otherwise, or in the earnings, business or
          operations of the Company and its subsidiaries, taken as a whole, from
          that set forth in the Prospectus.

               (k) There are no legal or governmental proceedings pending or, to
          the Company's knowledge, threatened to which the Company or any of its
          subsidiaries is a party or to which any of the properties of the
          Company or any of its subsidiaries is subject that are required to be
          described in the Registration Statement or the Prospectus and are not
          so described in the Registration Statement or Prospectus or a document
          incorporated therein by reference or any statutes, regulations,
          contracts or other documents that are required to be described in the
          Registration Statement or the Prospectus or to be filed as exhibits to
          the Registration Statement that are not described or filed as
          required.

               (l) Each of the Company and its subsidiaries has all necessary
          certificates, orders, permits, licenses, authorizations, consents and
          approvals of and from, and has made all declarations and filings with,
          all federal, state, local, foreign supranational, national and other
          governmental authorities, all self-regulatory organizations and all
          courts and tribunals, to own, lease, license and use its properties
          and assets and to conduct its business in the manner described in the
          Prospectus, except to the extent that the failure to so obtain or file
          would not have a material adverse effect on the Company and its
          subsidiaries, taken as a whole; and neither the Company nor any of its
          subsidiaries has received any notice of proceedings relating to
          revocation or modification of any such certificates, orders, permits,
          licenses, authorizations, consents or approvals, nor is the Company or
          any of its subsidiaries in violation of, or in default under, any
          federal, state, local, foreign supranational or national law,
          regulation, rule, decree, order or judgment applicable to the Company
          or any of its subsidiaries the effect of which, singly or in the
          aggregate, would have a material adverse effect on the prospects,
          condition, financial or otherwise, or on the earnings, business or
          operations of the Company and its subsidiaries, taken as a whole,
          except as described in the Prospectus. The radio licenses issued to
          the Company and its subsidiaries are not material to the business of
          the Company and its subsidiaries, taken as a whole.

               (m) Each preliminary prospectus filed as part of the registration
          statement as originally filed or as part of any amendment thereto, or
          filed pursuant to Rule 424 under the Securities Act, complied when so
          filed in all material respects with the Securities Act and the rules
          and regulations of the Commission thereunder.

               (n) The Company is not an "investment company" or an entity
          "controlled" by an "investment company", as such terms are defined in
          the Investment Company Act of 1940, as amended.
<PAGE>
 
                                        5


               (o) The Company and its subsidiaries are (i) in compliance with
          any and all applicable foreign, federal, state and local laws and
          regulations relating to the protection of human health and safety, the
          environment or hazardous or toxic substances or wastes, pollutants or
          contaminants ("Environmental Laws"), (ii) have received all permits,
          licenses or other approvals required of them under applicable
          Environmental Laws to conduct their respective businesses and (iii)
          are in compliance with all terms and conditions of any such permit,
          license or approval, except where such noncompliance with
          Environmental Laws, failure to receive required permits, licenses or
          other approvals or failure to comply with the terms and conditions of
          such permits, licenses or approvals would not, singly or in the
          aggregate, have a material adverse effect on the Company and its
          subsidiaries, taken as a whole.

               (p) Subsequent to the respective dates as of which information is
          given in the Registration Statement and the Prospectus, (1) the
          Company and its subsidiaries have not incurred any material liability
          or obligation, direct or contingent, nor entered into any material
          transaction not in the ordinary course of business; (2) the Company
          has not purchased any of its outstanding capital stock, nor declared,
          paid or otherwise made any dividend or distribution of any kind on its
          capital stock; and (3) there has not been any material change in the
          capital stock, short-term debt or long-term debt of the Company and
          its consolidated subsidiaries, except in each case as described in or
          contemplated by the Prospectus.

               (q) The Company and its subsidiaries have good and insurable
          title to all real property and good and marketable title to all
          personal property owned by them which is material to the business of
          the Company and its subsidiaries, in each case free and clear of all
          liens, encumbrances and defects except such as are described in the
          Prospectus or such as do not materially affect the value of such
          property and do not interfere with the use made and proposed to be
          made of such property by the Company and its subsidiaries; and any
          real property and buildings held under lease by the Company and its
          subsidiaries are held by them under valid and subsisting leases which
          are enforceable against the Company and, to the Company's knowledge,
          against the other parties thereto with such exceptions as are not
          material and do not interfere with the use made and proposed to be
          made of such property and buildings by the Company and its
          subsidiaries, in each case except as described in or contemplated by
          the Prospectus.

               (r) No material labor dispute with the employees of the Company
          or any of its subsidiaries exists, except as described in or
          contemplated by the Prospectus, or, to the knowledge of the Company,
          is imminent, which would have a material adverse effect upon the
          Company and its subsidiaries, taken as a whole; and the Company is not
          aware of any existing or imminent labor disturbance by the employees
          of any of its principal suppliers, manufacturers or contractors that
          could result in any material adverse change
<PAGE>
 
                                        6

          in the condition, financial or otherwise, or in the earnings, business
          or operations of the Company and its subsidiaries, taken as a whole.

               (s) The Company and each of its subsidiaries are insured by
          insurers of recognized financial responsibility against such losses
          and risks and in such amounts as the Company believes are prudent and
          are generally customary in the businesses in which they are engaged;
          since December 31, 1993, neither the Company nor any such subsidiary
          has been refused any insurance coverage sought or applied for; and
          neither the Company nor any such subsidiary has any reason to believe
          that it will not be able to renew its existing insurance coverage as
          and when such coverage expires or to obtain similar coverage from
          similar insurers as may be necessary to continue its business at a
          cost that would not materially and adversely affect the condition,
          financial or otherwise, or the earnings, business or operations of the
          Company and its subsidiaries, taken as a whole, except as described in
          or contemplated by the Prospectus.

               (t) The Company and each of its subsidiaries maintain a system of
          internal accounting controls sufficient to provide reasonable
          assurance that (1) transactions are executed in accordance with
          management's general and specific authorizations; (2) transactions are
          recorded as necessary to permit preparation of financial statements in
          conformity with generally accepted accounting principles and to
          maintain asset accountability; (3) access to assets is permitted only
          in accordance with management's general or specific authorization; and
          (4) the recorded accountability for assets is compared with the
          existing assets at reasonable intervals and appropriate action is
          taken with respect to any differences.

               (u) The Company is in compliance with all provisions of Section
          517.075, Florida Statutes (Chapter 92-198, Laws of Florida).

               (v) The Shares have been approved for quotation on the Nasdaq
          National Market System ("Nasdaq") by the National Association of
          Securities Dealers, Inc.

               (w) The waivers of registration rights by Fleet Venture
          Resources, Inc., Fleet Equity Partners VI, L.P., and Chisholm Partners
          II, L.P. (the "Fleet Affiliates"), true and accurate copies of which
          have been delivered to you on or before the date hereof, are in full
          force and effect.


                                       II.

          The Company hereby agrees to sell to the several Underwriters, and the
Underwriters, upon the basis of the representations and warranties herein
contained, but subject to the conditions hereinafter stated, agree, severally
and not jointly, to purchase from the
<PAGE>
 
                                        7

Company the respective number of Firm Shares set forth in Schedule I hereto
opposite their respective names at $_____ a share -- the purchase price.

          On the basis of the representations and warranties contained in this
Agreement, and subject to its terms and conditions, the Company agrees to sell
to the Underwriters the Additional Shares, and the Underwriters shall have a
one-time right, exercisable for a period of 30 days from the date of this
Agreement, to purchase, severally and not jointly, up to 262,500 Additional
Shares at the purchase price. Additional Shares may be purchased as provided in
Article IV hereof solely for the purpose of covering overallotments made in
connection with the offering of the Firm Shares. If any Additional Shares are to
be purchased, the Underwriters agree, severally and not jointly, to purchase the
number of Additional Shares (subject to such adjustments to eliminate fractional
shares as you may determine) that bears the same proportion to the total number
of Additional Shares to be purchased as the number of Firm Shares set forth in
Schedule I hereto opposite the name of such Underwriter bears to the total
number of Firm Shares.

          The Company hereby agrees that, without the prior written consent of
Morgan Stanley & Co. Incorporated, it will not (A) offer, pledge, sell, contract
to sell, sell any option or contract to purchase, purchase any option or
contract to sell, grant any option, right or warrant to purchase or otherwise
transfer or dispose of, directly or indirectly, any shares of Common Stock or
any securities convertible into or exercisable or exchangeable for Common Stock
or (B) enter into any swap or other agreement that transfers, in whole or in
part, any of the economic consequences of ownership of the Common Stock, whether
any such transaction described in clause (A) or (B) above is to be settled by
delivery of Common Stock or such other securities, in cash or otherwise for a
period of 120 days after the date of the Prospectus, other than (i) the Shares
to be sold hereunder, (ii) any shares of Common Stock issued by the Company upon
the exercise of an option or warrant or the conversion of a security outstanding
on the date hereof and described in the Prospectus or (iii) pursuant to the
Company's Employee Long-Term Incentive Plan, Employee Stock Purchase Plan and,
with respect to any new directors, the stock option plan for non-employee
directors, as such plans are in effect on the date of the Prospectus.


                                      III.

          The Company is advised by you that the Underwriters propose to make a
public offering of their respective portions of the Shares as soon after the
Registration Statement and this Agreement have become effective as in your
judgment is advisable. The Company is further advised by you that the Shares are
to be offered to the public initially at $____ a share (the public offering
price) and to certain dealers selected by you at a price that represents a
concession not in excess of $____ a share under the public offering price, and
that any Underwriter may allow, and such dealers may reallow, a concession, not
in excess of $____ a share, to any Underwriter or to certain other dealers.
<PAGE>
 
                                        8



                                       IV.

          Payment for the Firm Shares shall be made by certified or official
bank check or checks payable to the order of the Company in immediately
available funds at the office of Morgan Stanley & Co. Incorporated, 1585
Broadway, New York, New York, at 10:00 A.M., local time, on __________, 1996, or
at such other time on the same or such other date, not later than ________,
1996, as shall be designated in writing by you. The time and date of such
payment are hereinafter referred to as the "Closing Date".

          Payment for any Additional Shares shall be made by certified or
official bank check or checks payable to the order of the Company in immediately
available funds at the office of Shearman & Sterling, 599 Lexington Avenue, New
York, New York, at 10:00 A.M., local time, on such date (which may be the same
as the Closing Date but shall in no event be earlier than the Closing Date nor
later than ten business days after the giving of the notice hereinafter referred
to) as shall be designated in a written notice from you to the Company of your
determination, on behalf of the Underwriters, to purchase a number, specified in
said notice, of Additional Shares, or on such other date, in any event not later
than ______, 1996, as shall be designated in writing by you. The time and date
of such payment are hereinafter referred to as the "Option Closing Date". The
notice of the determination to exercise the option to purchase Additional Shares
and of the Option Closing Date may be given at any time within 30 days after the
date of this Agreement.

          Certificates for the Firm Shares and Additional Shares shall be in
definitive form and registered in such names and in such denominations as you
shall request in writing not later than two full business days prior to the
Closing Date or the Option Closing Date, as the case may be. The certificates
evidencing the Firm Shares and Additional Shares shall be delivered to you on
the Closing Date or the Option Closing Date, as the case may be, for the
respective accounts of the several Underwriters, with any transfer taxes payable
in connection with the transfer of the Shares to the Underwriters duly paid,
against payment of the purchase price therefor.


                                       V.

          The obligations of the Company and the several obligations of the
Underwriters hereunder are subject to the condition that the Registration
Statement shall have become effective not later than the date hereof.

          The several obligations of the Underwriters hereunder are subject to
the following further conditions:
<PAGE>
 
                                        9

               (a) Subsequent to the execution and delivery of this Agreement
          and prior to the Closing Date:

                    (i) there shall not have occurred any downgrading, nor shall
               any notice have been given of any intended or potential
               downgrading or of any review for a possible change that does not
               indicate the direction of the possible change, in the rating
               accorded any of the Company's securities by any "nationally
               recognized statistical rating organization" as such term is
               defined for purposes of Rule 436(g)(2) under the Securities Act;
               and

                    (ii) there shall not have occurred any change, or any
               development involving a prospective change, in the condition,
               financial or otherwise, or in the earnings, business or
               operations, of the Company and its subsidiaries, taken as a
               whole, from that set forth in the Registration Statement, that,
               in your judgment, is material and adverse and makes it, in your
               judgment, impracticable to market the Shares on the terms and in
               the manner contemplated in the Prospectus.

               (b) The Underwriters shall have received on the Closing Date a
          certificate, dated the Closing Date and signed, on behalf of the
          Company, by an executive officer of the Company, to the effect set
          forth in clause (a)(i) above and to the effect that the
          representations and warranties of the Company contained in this
          Agreement are true and correct as of the Closing Date and that the
          Company has complied with all of the agreements and satisfied all of
          the conditions on its part to be performed or satisfied hereunder on
          or before the Closing Date.

               The officer signing and delivering such certificate may rely upon
          the best of his knowledge as to proceedings threatened.

               (c) You shall have received on the Closing Date an opinion of
          Underberg & Kessler LLP, counsel for the Company, dated the Closing
          Date, to the effect that:

                    (i) the Company has been duly incorporated, is validly
               existing as a corporation in good standing under the laws of the
               State of Delaware, has the corporate power and authority to own
               its property and to conduct its business as described in the
               Prospectus and is duly qualified to transact business and is in
               good standing in each jurisdiction in which the conduct of its
               business or its ownership or leasing of property requires such
               qualification, except to the extent that the failure to be so
               qualified or be in good standing would not have a material
               adverse effect on the Company and its subsidiaries taken as a
               whole;

                    (ii) each subsidiary of the Company incorporated under the
               laws of a state of the United States has been duly incorporated,
               is validly existing as a
<PAGE>
 
                                       10

               corporation in good standing under the laws of the jurisdiction
               of its incorporation, has the corporate power and authority to
               own its property and to conduct its business as described in the
               Prospectus and is duly qualified to transact business and is in
               good standing in each jurisdiction in which the conduct of its
               business or its ownership or leasing of property requires such
               qualification, except to the extent that the failure to be so
               qualified or be in good standing would not have a material
               adverse effect on the Company and its subsidiaries taken as a
               whole;

                    (iii) the shares of Common Stock outstanding prior to the
               issuance of the Shares have been duly authorized and are validly
               issued, fully paid and non-assessable;

                    (iv) the execution and delivery by the Company of, and the
               performance by the Company of its obligations under, this
               Agreement will not contravene any provision of applicable law or
               the certificate of incorporation or by-laws of the Company or, to
               the best of such counsel's knowledge, any agreement or other
               instrument binding upon the Company or any of its subsidiaries
               or, to the best of such counsel's knowledge, any judgment, or
               decree of any governmental body, agency or court having
               jurisdiction over the Company or any subsidiary, and no consent,
               approval, authorization or order of or qualification with any
               governmental body or agency is required for the performance by
               the Company of its obligations under this Agreement, except such
               as may be required by the securities or Blue Sky laws of the
               various states in connection with the offer and sale of the
               Shares by the Underwriters; and

                    (v) the statements in the Prospectus under the caption
               "Shares Eligible for Future Sale", insofar as such statements
               constitute summaries of the documents or legal conclusions
               referred to therein, fairly summarize and fairly present, in all
               material respects, the information called for with respect to
               such documents or legal conclusions referred to therein.

               (d) You shall have received on the Closing Date an opinion of
          Nixon, Hargrave, Devans & Doyle LLP, special securities counsel for
          the Company, dated the Closing Date, to the effect that:

                    (i) the authorized capital stock of the Company conforms in
               all material respects as to legal matters to the description
               thereof contained in the Prospectus;

                    (ii) the Shares have been duly authorized and, when issued
               and delivered in accordance with the terms of this Agreement,
               will be validly issued,
<PAGE>
 
                                       11

               fully paid and non-assessable, and to such counsel's knowledge
               the issuance of such Shares will not be subject to any preemptive
               or similar rights;

                    (iii) this Agreement has been duly authorized, executed and
               delivered by the Company;

                    (iv) the statements (1) in the Prospectus under the captions
               "Description of Capital Stock" and "Underwriters" (except for the
               matters set forth in the sixth paragraph under such caption, as
               to which such counsel need express no opinion), (2) in the
               Registration Statement in Item 15, and (3) in the Company's most
               recent annual report on Form 10-K ("Form 10-K") incorporated by
               reference in the Prospectus under the caption "Item 13 - Certain
               Relationships and Related Transactions", in each case insofar as
               such statements constitute summaries of the documents or legal
               conclusions referred to therein, fairly summarize and fairly
               present, in all material respects, the information called for
               with respect to such documents or legal conclusions referred to
               therein;

                    (v) after due inquiry, such counsel does not know of any
               legal or governmental proceeding pending or threatened to which
               the Company or any of its subsidiaries is a party or to which any
               of the properties of the Company or any of its subsidiaries is
               subject that are required to be described in the Registration
               Statement or the Prospectus and are not so described in the
               Registration Statement or the Prospectus or a document
               incorporated by reference therein or of any statutes,
               regulations, contracts or other documents that are required to be
               described in the Registration Statement or the Prospectus or to
               be filed as exhibits to the Registration Statement that are not
               described or filed as required;

                    (vi) the Company is not an "investment company" or an entity
               "controlled" by an "investment company", as such terms are
               defined in the Investment Company Act of 1940, as amended; and

                    (vii) such counsel (1) is of the opinion that each document
               filed pursuant to the Exchange Act and incorporated by reference
               in the Registration Statement and the Prospectus (except for
               financial statements and notes thereto and schedules and other
               financial or statistical data included or incorporated by
               reference therein as to which such counsel need not express any
               opinion) complied when so filed as to form in all material
               respects with the Exchange Act and the rules and regulations of
               the Commission thereunder, and (2) is of the opinion that the
               Registration Statement and Prospectus (except for financial
               statements and notes thereto and schedules and other financial or
               statistical data included or incorporated by reference therein as
               to which such counsel need not express any opinion) comply as to
               form in all material respects with the Securities Act and the
               rules and regulations of the Commission thereunder. Such counsel
<PAGE>
 
                                       12

               shall also state that, although such counsel has not undertaken
               to determine independently, and therefore does not assume, except
               as expressly indicated in paragraphs (iv) and (v) above, any
               responsibility, explicitly or implicitly, for the accuracy,
               completeness or fairness of the statements contained in the
               Registration Statement and in the Prospectus, such counsel has
               participated in the preparation of the Registration Statement and
               Prospectus. Based upon and subject to the foregoing, and the
               other customary qualifications and limitations contained in such
               counsel's letter, nothing has come to such counsel's attention
               which causes such counsel to believe that (except for financial
               statements and notes thereto and schedules and other financial or
               statistical data included or incorporated by reference therein as
               to which such counsel need not express any belief) the
               Registration Statement and the prospectus included therein at the
               time the Registration Statement became effective contained any
               untrue statement of a material fact or omit to state a material
               fact required to be stated therein or necessary to make the
               statements therein not misleading or that the Prospectus contains
               any untrue statement of a material fact or omits to state a
               material fact necessary in order to make the statements therein,
               in light of the circumstances under which they were made, not
               misleading.

               (e) You shall have received on the Closing Date an opinion of
          Swidler & Berlin, special regulatory counsel for the Company, dated
          the Closing Date, to the effect set forth on Exhibit A hereto. The
          contents of the certificates referred to in Exhibit A shall be in form
          and content reasonably satisfactory to counsel for the Underwriters.

               (f) You shall have received on the Closing Date an opinion of
          McMillan Binch, Canadian counsel for the Company, dated the Closing
          Date, to the effect set forth on Exhibit B hereto. The contents of the
          certificates referred to in Exhibit B shall be in form and content
          reasonably satisfactory to counsel for the Underwriters.

               (g) You shall have received on the Closing Date an opinion of
          Osborne Clarke, United Kingdom counsel for the Company, dated the
          Closing Date, to the effect set forth on Exhibit C hereto. The
          contents of the certificates referred to in Exhibit C shall be in form
          and content reasonably satisfactory to counsel for the Underwriters.

               (h) You shall have received on the Closing Date an opinion of
          Roland, Fogel, Koblenz & Carr, New York counsel to the Company, dated
          the Closing Date, to the effect set forth on Exhibit D hereto. The
          contents of the certificates referred to in Exhibit D shall be in form
          and content reasonably satisfactory to counsel for the Underwriters.

               (i) You shall have received on the Closing Date an opinion of
          Shearman & Sterling, counsel for the Underwriters, dated the Closing
          Date, covering the matters referred to in subparagraphs (ii), (iii),
          (iv) (but only as to the statements in the
<PAGE>
 
                                       13

          Prospectus under "Description of Capital Stock" and "Underwriters"),
          (vi) and clause (2) of (vii) of paragraph (d) above.

          With respect to clause (2) of subparagraph (vii) of paragraph (d)
above, Shearman & Sterling may state that their opinion and belief are based
upon their participation in the preparation of the Registration Statement and
Prospectus and any amendments or supplements thereto (other than the documents
incorporated by reference) and review and discussion of the contents thereof
(including documents incorporated by reference), but are without independent
check or verification except as specified. Nixon, Hargrave, Devans & Doyle LLP,
Underberg & Kessler LLP and Shearman & Sterling need not express any opinion or
belief with respect to matters governed by or related to (i) federal, state,
local or foreign communications law or the rules, regulations or policies of the
FCC thereunder or with respect thereto, or (ii) any law other than the federal
law of the United States of America, the law of the State of New York or the
General Corporation Law of the State of Delaware. With regard to the belief
expressed by Nixon, Hargrave, Devans & Doyle LLP and Shearman & Sterling
pursuant to paragraphs (d) and (i) above, insofar as such belief may relate to
statements in the prospectus contained in the Registration Statement or the
Prospectus under the caption "Shares Eligible for Future Sale", such counsel may
rely upon an opinion of Underberg & Kessler.

               (j) You shall have received, on each of the date hereof and the
          Closing Date, a letter dated the date hereof or the Closing Date, as
          the case may be, in form and substance satisfactory to you, from
          Arthur Andersen LLP, independent public accountants, containing
          statements and information of the type ordinarily included in
          accountants' "comfort letters" to underwriters with respect to the
          financial statements and certain financial information contained in or
          incorporated by reference into the Registration Statement and the
          Prospectus.

               (k) The "lock-up" agreements between you and officers and
          directors of the Company and the Fleet Affiliates relating to sales of
          shares of Common Stock of the Company or any securities convertible
          into or exercisable or exchangeable for such Common Stock, delivered
          to you on or before the date hereof, shall be in full force and effect
          on the Closing Date.

               (l) The waivers of registration rights by the Fleet Affiliates,
          true and accurate copies of which have been delivered to you on or
          before the date hereof, shall be in full force and effect on the
          Closing Date.

               (m) The Shares shall have been approved for quotation on Nasdaq
          by the National Association of Securities Dealers, Inc.

               (n) You shall have received on the Closing Date a certificate of
          status for each of ACC TelEnterprises Ltd. and its subsidiaries from
          the respective jurisdiction of
<PAGE>
 
                                       14

          incorporation and the jurisdictions in which ACC TelEnterprises Ltd.
          and its subsidiaries transact business.

               (o) You shall have received on the Closing Date such other
          certificates and documents as you may reasonably request.

          The several obligations of the Underwriters to purchase Additional
Shares hereunder are subject to the delivery to you on the Option Closing Date
of such documents as you may reasonably request with respect to the good
standing of the Company, the due authorization and issuance of the Additional
Shares and other matters related to the issuance of the Additional Shares.


                                       VI.

          In further consideration of the agreements of the Underwriters herein
contained, the Company covenants as follows:

               (a) To furnish to you, without charge, three signed copies of the
          Registration Statement (including exhibits thereto and conformed
          copies of documents incorporated by reference) and to each other
          Underwriter a conformed copy of the Registration Statement (without
          exhibits thereto but including documents incorporated by reference)
          and, during the period mentioned in paragraph (c) below, as many
          copies of the Prospectus, any documents incorporated therein by
          reference, and any supplements and amendments thereto as you may
          reasonably request. In the case of the Prospectus, to use its
          reasonable best efforts to furnish to you copies of the Prospectus in
          New York City and in London, prior to 5:00 p.m., on the business day
          next succeeding the date of this Agreement, in such quantities as you
          reasonably request.

               (b) Before amending or supplementing the Registration Statement
          or the Prospectus, to furnish to you a copy of each such proposed
          amendment or supplement and to file no such proposed amendment or
          supplement to which you reasonably object.

               (c) If, during such period after the first date of the public
          offering of the Shares as in the opinion of your counsel the
          Prospectus is required by law to be delivered in connection with sales
          by an Underwriter or dealer, any event shall occur or condition exist
          as a result of which it is necessary to amend or supplement the
          Prospectus in order to make the statements therein, in the light of
          the circumstances when the Prospectus is delivered to a purchaser, not
          misleading, or if, in the opinion of your counsel, it is necessary to
          amend or supplement the Prospectus to comply with law, forthwith to
          prepare, file with the Commission and furnish, at its own expense, to
          the Underwriters and to the dealers (whose names and addresses you
          will furnish to the Company) to
<PAGE>
 
                                       15

          which Shares may have been sold by you on behalf of the Underwriters
          and to any other dealers upon request, either amendments or
          supplements to the Prospectus so that the statements in the Prospectus
          as so amended or supplemented will not, in the light of the
          circumstances when the Prospectus is delivered to a purchaser, be
          misleading or so that the Prospectus, as amended or supplemented, will
          comply with law.

               (d) To endeavor to qualify the Shares for offer and sale under
          the securities or Blue Sky laws of such jurisdictions as you shall
          reasonably request and to pay all expenses (including reasonable fees
          and disbursements of counsel) in connection with such qualification
          and in connection with any review of the offering of the Shares by the
          National Association of Securities Dealers, Inc.

               (e) To make generally available to the Company's security holders
          and to you as soon as practicable an earning statement that satisfies
          the provisions of Section 11(a) of the Securities Act and the rules
          and regulations of the Commission thereunder.

               (f) Whether or not the transactions contemplated in this
          Agreement are consummated or this Agreement is terminated, to pay or
          cause to be paid the following: (i) the fees, disbursements and
          expenses of the Company's counsel and the Company's accountants in
          connection with the registration and delivery of the Shares under the
          Securities Act and all other fees or expenses in connection with the
          preparation and filing of the Registration Statement, any preliminary
          prospectus, the Prospectus and amendments and supplements to any of
          the foregoing, including all printing costs associated therewith, and
          the mailing and delivering of copies thereof to the Underwriters and
          dealers, in the quantities hereinabove specified, (ii) all costs and
          expenses related to the transfer and delivery of the Shares to the
          Underwriters, including any transfer or other taxes payable thereon,
          (iii) the cost of printing or producing any Blue Sky or Legal
          Investment memorandum in connection with the offer and sale of the
          Shares under state securities laws and all expenses in connection with
          the qualification of the Shares for offer and sale under state
          securities laws as provided in paragraph (d) above, including filing
          fees and the reasonable fees and disbursements of counsel for the
          Underwriters in connection with such qualification and in connection
          with the Blue Sky or Legal Investment memorandum, (iv) all filing fees
          and disbursements of counsel to the Underwriters incurred in
          connection with the review and qualification of the offering by the
          National Association of Securities Dealers, Inc., (v) all costs and
          expenses incidental to listing the Shares on Nasdaq, (vi) the cost of
          printing certificates representing the Shares, (vii) the costs and
          charges of any transfer agent, registrar or depositary, (viii) the
          costs and expenses of the Company relating to investor presentations
          on any "road show" undertaken in connection with the marketing of the
          offering, including, without limitation, expenses associated with the
          production of road show slides and graphics, fees and expenses of any
          consultants engaged in connection with the road show presentations
          with the prior approval of the Company, travel and lodging expense of
          the
<PAGE>
 
                                       16

          representatives and officers of the Company and any such consultants,
          and the cost of any aircraft chartered in connection with the road
          show and (ix) all other costs and expenses incident to the performance
          of the obligations of the Company hereunder for which provision is not
          otherwise made in this paragraph. It is understood, however, that
          except as provided in this Section, Article VII and the third
          paragraph of Article IX below, the Underwriters will pay all of their
          costs and expenses, including fees and disbursements of their counsel,
          stock transfer taxes payable on resale of any of the Shares by them,
          and any advertising expenses connected with any offers they may make.


                                      VII.

          The Company agrees to indemnify and hold harmless each Underwriter and
each person, if any, who controls any Underwriter within the meaning of either
Section 15 of the Securities Act or Section 20 of the Exchange Act, from and
against any and all losses, claims, damages and liabilities (including, without
limitation, any legal or other expenses reasonably incurred by any Underwriter
or any such controlling person in connection with defending or investigating any
such action or claim) caused by any untrue statement or alleged untrue statement
of a material fact contained in the Registration Statement or any amendment
thereof, any preliminary prospectus or the Prospectus (as amended or
supplemented if the Company shall have furnished any amendments or supplements
thereto), or caused by any omission or alleged omission to state therein a
material fact required to be stated therein or necessary to make the statements
therein not misleading, except insofar as such losses, claims, damages or
liabilities are caused by any such untrue statement or omission or alleged
untrue statement or omission based upon information relating to any Underwriter
furnished to the Company in writing by such Underwriter through you expressly
for use therein; provided, however, that the foregoing indemnity agreement with
                 --------  -------
respect to any preliminary prospectus shall not inure to the benefit of any
Underwriter from whom the person asserting any such losses, claims, damages or
liabilities purchased Shares, or any person controlling such Underwriter, if a
copy of the Prospectus (as then amended or supplemented if the Company shall
have furnished any amendments or supplements thereto) was not sent or given by
or on behalf of such Underwriter to such person, if required by law so to have
been delivered, at or prior to the written confirmation of the sale of the
Shares to such person, and if the Prospectus (as so amended or supplemented)
would have cured the defect giving rise to such losses, claims, damages or
liabilities.

          Each Underwriter agrees, severally and not jointly, to indemnify and
hold harmless the Company, its directors, its officers who sign the Registration
Statement and each person, if any, who controls the Company within the meaning
of either Section 15 of the Securities Act or Section 20 of the Exchange Act to
the same extent as the foregoing indemnity from the Company to such Underwriter,
but only with reference to information relating to such Underwriter furnished to
the Company in writing by such Underwriter through you expressly
<PAGE>
 
                                       17

for use in the Registration Statement, any preliminary prospectus, the
Prospectus or any amendments or supplements thereto.

          In case any proceeding (including any governmental investigation)
shall be instituted involving any person in respect of which indemnity may be
sought pursuant to either of the two preceding paragraphs, such person (the
"indemnified party") shall promptly notify the person against whom such
indemnity may be sought (the "indemnifying party") in writing and the
indemnifying party, upon request of the indemnified party, shall retain counsel
reasonably satisfactory to the indemnified party to represent the indemnified
party and any others the indemnifying party may designate in such proceeding and
shall pay the reasonable fees and disbursements of such counsel related to such
proceeding. In any such proceeding, any indemnified party shall have the right
to retain its own counsel, but the fees and expenses of such counsel shall be at
the expense of such indemnified party unless (i) the indemnifying party and the
indemnified party shall have mutually agreed to the retention of such counsel or
(ii) the named parties to any such proceeding (including any impleaded parties)
include both the indemnifying party and the indemnified party and representation
of both parties by the same counsel would be inappropriate due to actual or
potential differing interests between them. It is understood that the
indemnifying party shall not, in respect of the legal expenses of any
indemnified party in connection with any proceeding or related proceedings in
the same jurisdiction, be liable for the fees and expenses of more than one
separate firm (in addition to any local counsel) for all such indemnified
parties and that all such fees and expenses shall be reimbursed as they are
incurred. In the case of any such separate firm for the Underwriters and such
control persons of Underwriters, such firm shall be designated in writing by
Morgan Stanley & Co. Incorporated. In the case of any such separate firm for the
Company, and such directors, officers and control persons of the Company, such
firm shall be designated in writing by the Company. The indemnifying party shall
not be liable for any settlement of any proceeding effected without its written
consent, but if settled with such consent or if there be a final judgment for
the plaintiff, the indemnifying party agrees to indemnify the indemnified party
from and against any loss or liability by reason of such settlement or judgment.
Notwithstanding the foregoing sentence, if at any time an indemnified party
shall have requested an indemnifying party to reimburse the indemnified party
for fees and expenses of counsel as contemplated by the second and third
sentences of this paragraph, the indemnifying party agrees that it shall be
liable for any settlement of any proceeding effected without its written consent
if (i) such settlement is entered into more than 30 days after receipt by such
indemnifying party of the aforesaid request and (ii) such indemnifying party
shall not have reimbursed the indemnified party in accordance with such request
prior to the date of such settlement. No indemnifying party shall, without the
prior written consent of the indemnified party, effect any settlement of any
pending or threatened proceeding 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 claims that are the subject matter
of such proceeding.
<PAGE>
 
                                       18

          If the indemnification provided for in the first or second paragraph
of this Article VII is unavailable to an indemnified party or insufficient in
respect of any losses, claims, damages or liabilities referred to therein, then
each indemnifying party under such paragraph, in lieu of indemnifying such
indemnified party thereunder, shall contribute to the amount paid or payable by
such indemnified party as a result of such losses, claims, damages or
liabilities (i) in such proportion as is appropriate to reflect the relative
benefits received by the Company on the one hand and the Underwriters on the
other hand from the offering of the Shares 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 on the one hand and of the
Underwriters on the other hand in connection with the statements or omissions
that resulted in such losses, claims, damages or liabilities, as well as any
other relevant equitable considerations. The relative benefits received by the
Company on the one hand and the Underwriters on the other hand in connection
with the offering of the Shares shall be deemed to be in the same respective
proportions as the net proceeds from the offering of the Shares (before
deducting expenses) received by the Company and the total underwriting discounts
and commissions received by the Underwriters, in each case as set forth in the
table on the cover of the Prospectus, bear to the aggregate public offering
price of the Shares. The relative fault of the Company on the one hand and the
Underwriters on the other hand 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 by the Underwriters and the parties' relative intent,
knowledge, access to information and opportunity to correct or prevent such
statement or omission. The Underwriters' respective obligations to contribute
pursuant to this Article VII are several in proportion to the respective number
of Shares they have purchased hereunder, and not joint.

          The Company and the Underwriters agree that it would not be just or
equitable if contribution pursuant to this Article VII were determined by pro
                                                                          ---
rata allocation (even if the Underwriters were treated as one entity for such
----
purpose) or by any other method of allocation that does not take account of the
equitable considerations referred to in the immediately preceding paragraph. The
amount paid or payable by an indemnified party as a result of the losses,
claims, damages and liabilities referred to in the immediately preceding
paragraph shall be deemed to include, subject to the limitations set forth
above, any legal or other expenses reasonably incurred by such indemnified party
in connection with investigating or defending any such action or claim.
Notwithstanding the provisions of this Article VII, no Underwriter shall be
required to contribute any amount in excess of the amount by which the total
price at which the Shares underwritten by it and distributed to the public were
offered to the public exceeds the amount of any damages that such Underwriter
has otherwise been required to pay by reason of such untrue or alleged statement
or omission or alleged omission. No person guilty of fraudulent
misrepresentation (within the meaning of Section 11(f) of the Securities Act)
shall be entitled to contribution from any person who was not guilty of such
fraudulent misrepresentation.
<PAGE>
 
                                       19

The remedies provided for in this Article VII are not exclusive and shall not
limit any rights or remedies which may otherwise be available to any indemnified
party at law or in equity.

          The indemnity and contribution provisions contained in this Article
VII and the representations and warranties of the Company contained in this
Agreement shall remain operative and in full force and effect regardless of (i)
any termination of this Agreement, (ii) any investigation made by or on behalf
of any Underwriter or any person controlling any Underwriter or by or on behalf
of the Company, its officers or directors or any person controlling the Company
and (iii) acceptance of and payment for any of the Shares.


                                      VIII.

          This Agreement shall be subject to termination by notice given by you
to the Company, if (a) after the execution and delivery of this Agreement and
prior to the Closing Date (i) trading generally shall have been suspended or
materially limited on or by, as the case may be, any of the New York Stock
Exchange, the American Stock Exchange, the National Association of Securities
Dealers, Inc., the Chicago Board of Options Exchange, the Chicago Mercantile
Exchange or the Chicago Board of Trade, (ii) trading of any securities of the
Company shall have been suspended on any exchange or in any over-the-counter
market, (iii) a general moratorium on commercial banking activities in New York
shall have been declared by either federal or New York State authorities or (iv)
there shall have occurred any outbreak or escalation of hostilities or any
change in financial markets or any calamity or crisis that, in your judgment, is
material and adverse and (b) in the case of any of the events specified in
clauses (a)(i) through (iv), such event singly or together with any other such
event makes it, in your judgment, impracticable to market the Shares on the
terms and in the manner contemplated in the Prospectus.


                                       IX.

          This Agreement shall become effective upon the later of (a) execution
and delivery hereof by the parties hereto and (b) release of notification of the
effectiveness of the Registration Statement by the Commission.

          If, on the Closing Date or the Option Closing Date, as the case may
be, any one or more of the Underwriters shall fail or refuse to purchase Shares
that it or they have agreed to purchase hereunder on such date, and the
aggregate number of Shares which such defaulting Underwriter or Underwriters
agreed but failed or refused to purchase is not more than one-tenth of the
aggregate number of the Shares to be purchased on such date, the other
Underwriters shall be obligated severally in the proportions that the number of
Firm Shares set forth opposite their respective names in Schedule I bears to the
aggregate number of Firm Shares set forth opposite
<PAGE>
 
                                       20

the names of all such nondefaulting Underwriters, or in such other proportions
as you may specify, to purchase the Shares which such defaulting Underwriter or
Underwriters agreed but failed or refused to purchase on such date; provided
                                                                    --------
that in no event shall the number of Shares that any Underwriter has agreed to
purchase pursuant to Article II be increased pursuant to this Article IX by an
amount in excess of one-ninth of such number of Shares without the written
consent of such Underwriter. If, on the Closing Date or the Option Closing Date,
as the case may be, any Underwriter or Underwriters shall fail or refuse to
purchase Shares and the aggregate number of Shares with respect to which such
default occurs is more than one-tenth of the aggregate number of Shares to be
purchased on such date, and arrangements satisfactory to you and the Company for
the purchase of such Shares are not made within 36 hours after such default,
this Agreement shall terminate without liability on the part of any
non-defaulting Underwriter or the Company. In any such case either you or the
Company shall have the right to postpone the Closing Date or the Option Closing
Date, as the case may be, but in no event for longer than seven days, in order
that the required changes, if any, in the Registration Statement and in the
Prospectus or in any other documents or arrangements may be effected. Any action
taken under this paragraph shall not relieve any defaulting Underwriter from
liability in respect of any default of such Underwriter under this Agreement.

          If this Agreement shall be terminated by the Underwriters, or any of
them, because of any failure or refusal on the part of the Company to comply
with the terms or to fulfill any of the conditions of this Agreement, or if for
any reason the Company shall be unable to perform its obligations under this
Agreement, the Company will reimburse the Underwriters or such Underwriters as
have so terminated this Agreement with respect to themselves, severally, for all
out-of-pocket expenses (including the reasonable fees and disbursements of their
counsel) reasonably incurred by such Underwriters in connection with this
Agreement or the offering contemplated hereunder.

          This Agreement may be signed in two or more counterparts, each of
which shall be an original, with the same effect as if the signatures thereto
and hereto were upon the same instrument.
<PAGE>
 
                                       21

          This Agreement shall be governed by the laws of the State of New York.

                                               Very truly yours,

                                               ACC CORP.



                                               By______________________________
                                                 Name:
                                                 Title:


Accepted, ___________ 1996

MORGAN STANLEY & CO.
  INCORPORATED
WHEAT, FIRST SECURITIES, INC.

Acting severally on behalf of themselves 
  and the several Underwriters 
  named in Schedule I hereto.

By Morgan Stanley & Co.
     Incorporated


By__________________________
  Name:
  Title:
<PAGE>
 
                                   SCHEDULE I

                                  Underwriters
                                  ------------
                                                              Number of
                                                             Firm Shares
    Underwriter                                            To Be Purchased
    -----------                                            ---------------
Morgan Stanley & Co. Incorporated

Wheat, First Securities, Inc.














Total Firm Shares..........................................   1,750,000
                                                              =========
