

                                ACTEL CORPORATION

                                  Supplement to
            Offer to Exchange All Outstanding Options for New Options
                            (the "Offer Supplement")

     The offer and withdrawal rights expire at 9:00 p.m., Pacific Daylight Time,
on June 29, 2001, unless the offer is extended.

     The Offer to Exchange all Outstanding Options for New Options dated June 1,
2001 (the "Offer to Exchange") is amended and  supplemented  as set forth below.
The item numbers  listed below refer to the item numbers  contained in the Offer
to Exchange.

     o    The sentence under Item 5 amends and restates the last sentence of the
          first paragraph of the Offer to Exchange.

     o    The two  paragraphs  under  Item 17 amend  and  restate  the first two
          paragraphs of the Offer to Exchange.

     o    The information  under the other item numbers listed below  supplement
          the Offer to Exchange.

Except as amended or  supplemented  below,  the original terms and conditions of
the Offer to Exchange remain in effect.

     This Offer  Supplement is being  transmitted to you via electronic mail and
is posed on the Actel  intranet.  Hard  copies of this Offer  Supplement  may be
obtained  at no cost by  contacting  us at  Actel  Corporation,  Attn:  Investor
Relations, 955 East Arques Avenue (Building 3), Sunnyvale,  California 94086, or
telephoning us at (408) 522-2341.

     5.   Acceptance of Options for Exchange and Issuance of New Options
     -------------------------------------------------------------------

     Promptly after we accept and cancel options tendered for exchange,  we will
issue to you a Promise  to Grant  Stock  Option(s),  by which we will  commit to
grant stock options covering the same number of shares as the options  cancelled
pursuant to this  offer,  provided  that you remain an eligible  employee on the
date on which the grant is to be made.

     9.   Information Concerning Actel
     ---------------------------------

     Set forth below is a selected  summary of our  financial  information.  The
selected  historical  statement of operations  data for the years ended December
31, 1999 and 2000, and the selected historical balance sheet data as of December
31, 2000, have been derived from the consolidated  financial statements included
in our Annual  Report on Form 10-K for the year ended  December 31, 2000,  which
have been  audited by Ernst & Young LLP,  independent  public  accountants.  The
selected  historical  statement  of  operations  data for the three months ended
March 31, 2000 and 2001,  and the selected  historical  balance sheet data as of
March 31, 2001,  which are included in our Quarterly Report on Form 10-Q for the
quarter  ended March 31, 2001,  are  unaudited  but  include,  in the opinion of
management,  all adjustments,  consisting only of normal recurring  adjustments,
necessary for a fair presentation of such data. The information  presented below
should be read together with our consolidated  financial  statements and related
notes.


<PAGE>


                                ACTEL CORPORATION

                          Summary Financial Information
                      (in thousands, except per share data)

<TABLE>
<CAPTION>
                                                                                           December 31,
                                                                 March 31    ----------------------------------------
                                                                   2001          2000          1999          1998
                                                               ------------  ------------  ------------  ------------
<S>                                                            <C>           <C>           <C>           <C>
(1) Summarized financial information:
     Current assets.......................................     $    220,129  $    229,285  $    177,884  $    138,512
     Noncurrent assets....................................           84,718        83,149        75,227        41,196
     Current liabilities..................................           66,779        82,333        69,066        52,654
     Noncurrent liabilities...............................            1,839            --         5,415            --
</TABLE>

<TABLE>
<CAPTION>
                                                     Three Months Ended
                                                         March 31,                   Years Ended December 31,
                                                 --------------------------  ----------------------------------------
                                                     2001          2000          2000          1999          1998
                                                 ------------  ------------  ------------  ------------  ------------
<S>                                              <C>           <C>           <C>           <C>           <C>
     Net revenues..............................  $     45,034  $     50,666  $    226,419  $    171,661  $    154,427
     Gross margin..............................        28,160        31,458       141,739       105,274        92,785
     Income from operations....................         3,463        10,555        38,478        22,244        19,822
     Net income................................         2,795         8,099        41,445        17,638        14,987

(2)  Earnings per share from continuing
     operations:
     Basic.....................................          0.12          0.36          1.77          0.81          0.71
     Diluted...................................          0.11          0.32          1.58          0.76          0.68

(3)  Earnings per share from continuing
     operations:
     Basic.....................................          0.12          0.36          1.77          0.81          0.71
     Diluted...................................          0.11          0.32          1.58          0.76          0.68

(4)  Ratio of earnings to fixed charges (a).            15.30         35.62         51.71         19.35         21.18

(5)  Book value per share (b)...............            10.02          8.65          9.86          7.94          6.00

(6)  Not applicable
</TABLE>
------------------------------------------------------------

     (a)  Ratio of  earnings to fixed  charges is  computed  by  dividing  fixed
          charges into earnings  before income taxes plus fixed  charges.  Fixed
          charges consist of interest expense (including  capitalized  interest,
          amortization of original issue  discount,  and debt issuance costs, as
          applicable)  and the  estimated  portion  of  operating  lease  rental
          expense that represents the interest factor (deemed to be one-third of
          lease payments).

     (b)  Book  value  per  share  is   computed  by   dividing   total   common
          shareholders' equity by the actual common shares outstanding as of the
          date indicated.


     10.  Interests of Directors and  Officers;  Transactions  and  Arrangements
     ---------------------------------------------------------------------------
          Concerning the Options
          ----------------------


     The  following  table sets forth the number of options  held by each of our
executive offers and directors:

<TABLE>
<CAPTION>
                                                    1986 Plan                1995 Plan               All Plans
                                               --------------------   --------------------    ----------------------
                    Name                        Options        %        Options       %         Options         %
-------------------------------------------    ----------   -------   ----------   -------    ------------    ------
<S>                                               <C>          <C>        <C>         <C>          <C>          <C>
John C. East                                      406,397      9.0%       86,697      5.8%         493,094      7.7%
Anthony Farinaro                                  131,444      2.9         2,556      0.2          134,000      2.1
James R. Fiebiger                                       0      0.0             0      0.0           15,000      0.2
Esmat Z. Hamdy                                    140,572      3.1        31,342      2.1          171,914      2.7
Jos C. Henkens                                          0      0.0             0      0.0           27,500      0.4
Paul Indaco                                       192,687      4.3         4,313      0.3          197,000      3.1
Jacob S. Jacobson                                       0      0.0             0      0.0           25,000      0.4
Dennis G. Kish                                    103,424      2.3        46,576      3.1          150,000      2.3
Fares N. Mubarak                                  143,420      3.2        34,641      2.3          178,061      2.8
Henry L. Perret                                   121,455      2.7        24,296      1.6          145,751      2.3
Frederic N. Schwettmann                                 0      0.0             0      0.0           47,500      0.7
Robert G. Spencer                                       0      0.0             0      0.0           42,500      0.7
David L. Van De Hey                               107,524      2.4        15,102      1.0          122,626      1.9

</TABLE>

     o    On May 7, 2001,  Mr.  Farinaro sold 1,245 shares of Actel common stock
          at a weighted average sale price of $22.50 per share.

     17.  Miscellaneous
     ------------------

     Our SEC reports referred to above include forward-looking statements, which
are made  pursuant  to the safe  harbor  provisions  of the  Private  Securities
Litigation  Reform  Act  of  1995.  Words  such  as  "anticipates,"  "believes,"
"estimates,"  "expects,"  intends," "plans," "projects," "seeks," and variations
of  such  words  and  similar   expressions   are   intended  to  identify   the
forward-looking  statements.  The forward-looking statements include projections
and  trends  relating  to  acquisitions;  amortization  of  goodwill  and  other
acquisition-related   expenses;   average   selling   prices;   competition  and
competitive  factors;  customer  service and  technical  support;  distributors;
dividends and retention of earnings; embedded logic strategy; employee relations
and  hiring;  expansion  and growth;  export  licensing;  facilities;  financial
condition and liquidity;  gross margin;  hardware and software  availability and
features;  intellectual property protection and claims;  issuance and repurchase
of securities  and dilution;  litigation  and disputes;  markets,  including the
e-appliance,  embedded logic, and space markets;  process  development;  product
availability  and delivery;  research and  development  expenditures;  revenues,
including   international   sales;   selling,    general,   and   administrative
expenditures;   useful  life  estimates;  and  wafer  yields.  The  safe  harbor
provisions of the Private Securities Litigation Reform Act of 1995 do not extend
to forward-looking  statements contained in this Offer Supplement,  the Offer to
Exchange,  the Memorandum from Barbara McArthur dated June 1, 2001, the Election
Form, or the Notice to Change Election from Accept to Reject.

     Each  forward-looking  statement is based on  expectations  and projections
about the semiconductor  industry and programmable logic market, and assumptions
made by us that reflect our best judgment based on other factors known by us, at
the time the forward-looking  statement is made, but none of the forward-looking
statements are guarantees of future performance. Thus, actual events and results
may differ  materially from those  expressed or forecast in the  forward-looking
statements due to the risk factors  identified in our Annual Report on Form 10-K
filed on April 2, 2001, or for other reasons.  These risks include,  but are not
limited to:

     o    "blank check" preferred stock;

     o    change in control arrangements;

     o    competition;

     o    customer concentration;

     o    dependence on communications customers;

     o    dependence on customized manufacturing processes;

     o    dependence on design wins;

     o    dependence on independent assembly subcontractors;

     o    dependence on independent software and hardware developers;

     o    dependence on independent wafer manufacturers;

     o    dependence on international operations;

     o    dependence on key personnel;

     o    dependence on military and aerospace customers;

     o    dividend policy;

     o    fluctuations  in  operating  results,  including  booking and shipment
          uncertainties, supply problems, and price erosion;

     o    force majeure;

     o    future capital needs;

     o    gross margin;

     o    management of growth;

     o    manufacturing yields;

     o    one-time programmability and in-system reprogrammability;

     o    patent infringement;

     o    potential acquisitions;

     o    protection of intellectual property;

     o    reliance on distributors;

     o    reliance on international sales;

     o    semiconductor industry risks;

     o    technological change and dependence on new product development; and

     o    volatility of stock.



                                                             Actel Corporation
                                                             June 20, 2001



