DISTRIBUTION AGREEMENT

                                                               November __, 2001
UBS Warburg LLC 677 Washington Blvd.
Stamford, Connecticut 06901


Ladies and Gentlemen:

     Aphton Corporation, a Delaware corporation (the "Company"), confirms its
agreement with UBS Warburg LLC, as agent ("you" or the "Agent") with respect to
the issuance and sale from time to time by the Company, in the manner and
subject to the terms and conditions described below, up to an aggregate of
_______ shares (the "Maximum Number of Shares") of common stock, $0.001 par
value per share (the "Common Stock"), of the Company. Such shares are
hereinafter collectively referred to as the "Shares." The Shares are described
in the Prospectus referred to below.

     The Company has filed with the Securities and Exchange Commission (the
"Commission") a registration statement on [Form S-3 (No. 333-________)] for the
registration of at least the Maximum Number of Shares, under the Securities Act
of 1933, as amended, and the rules and regulations of the Commission thereunder
(collectively, the "Act"), and the offering of the Shares from time to time in
accordance with Rule 415 under the Act, and the Company has filed such
post-effective amendments thereto as may be required prior to any sale of Shares
by the Company. Such registration statement (as so amended, if applicable) has
been declared effective by the Commission and is referred to herein as the
"Registration Statement." The final prospectus and all applicable amendments or
supplements thereto (including any pricing supplements relating to the sale of
Shares from time to time), in the form first furnished to the Agent, are
collectively referred to herein as the "Prospectus." All references to the
"Registration Statement" and the "Prospectus" also shall be deemed to include
all documents incorporated therein by reference pursuant to the Securities
Exchange Act of 1934, as amended (the "1934 Act"), prior to any delivery by the
Company of any Purchase Notice (as defined herein); provided, that if the
Company files a registration statement with the Commission pursuant to Rule
462(b) under the Act (the "Rule 462(b) Registration Statement"), then, after
such filing, all references to the "Registration Statement" also shall be deemed
to include the Rule 462(b) Registration Statement. A "preliminary prospectus"
shall be deemed to refer to any prospectus used before the registration
statement became effective and any prospectus furnished by the Company after the
registration statement became effective and prior to any delivery by the Company
of any Purchase Notice which omitted information to be included in a form of
prospectus filed with the Commission pursuant to Rule 424(b) under the Act. For
purposes of this Agreement, all references to the Registration Statement,
Prospectus or preliminary prospectus or to any amendment or supplement thereto
shall be deemed to include any copy filed

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<PAGE>

with the Commission pursuant to its Electronic Data Gathering, Analysis and
Retrieval system ("EDGAR").

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     The Company and the Agent agree as follows:

     1. Issuance and Sale.

     (a)  Upon the basis of the representations and warranties and subject to
          the terms and conditions herein set forth on any Exchange Business Day
          (as defined below) selected by the Company from the date hereof until
          the earlier of (i) January 21, 2002, and (ii) the termination of this
          Agreement pursuant to Section 9 or 10 (the "Termination Date") (the
          period beginning on the date hereof and ending on the earlier of such
          dates, the "Commitment Period"), (A) with respect to purchases by
          Agent as principal, the Company shall sell to the Agent, and the Agent
          agrees to purchase from the Company, the number of Shares determined
          in the manner and on the terms set forth herein, and (B) with respect
          to purchases by Agent as agent, the Agent and the Company shall enter
          into an agreement regarding the issuance and sale of the number of
          Shares determined in the manner and on the terms set forth below. The
          Commitment Period may be extended until [April 20, 2002] upon the
          Agent's delivery to the Company of a written notice on any date prior
          to January 7, 2002 to that effect and the Company's acceptance of such
          request, provided that such extension is contingent upon the Company
          providing the Agent with any due diligence materials and information
          requested by the Agent necessary for the Agent to satisfy its due
          diligence obligations, and satisfaction of the other terms and
          conditions set forth herein.

     (b)  Subject to the terms and conditions set forth below, the Company
          appoints you as Agent in connection with the offer and sale of Shares.
          In the case of sales of Blocks (as defined below), the Agent agrees,
          as agent of the Company, to use its best efforts when requested in the
          manner described herein to solicit offers to purchase the Shares upon
          the terms and conditions set forth in the Prospectus and as agreed to
          with the Company. Each of the Agent and the Company agrees to perform
          the respective agreements specifically provided to be performed by it
          herein. The Company and the Agent agree that any Shares, the placement
          of which the Agent arranges, shall be placed by such Agent in reliance
          on the representations, warranties, covenants and agreements of the
          Company contained herein and shall be subject to the terms and
          conditions set forth herein. The Agent shall not have any obligation
          whatsoever to purchase Blocks from the Company as principal, but the
          Agent and the Company may agree expressly from time to time that the
          Agent shall purchase the Blocks as principal on terms and conditions
          to be agreed.

     (c)  Following delivery of a Purchase Notice (as defined below), the Agent
          will communicate to the Company, orally, each offer to purchase Blocks
          solicited by such Agent on an agency basis. The Agent shall have the
          right, in its sole discretion, reasonably exercised, to reject any
          proposed purchase of Blocks, as a whole or in part, by persons
          solicited by the Agent and any such rejection shall not be deemed a
          breach of the Agreement contained herein. The Company may accept or
          reject any proposed purchase of the Blocks, in whole or in part, and
          any such rejection shall not be deemed a breach of the Company's
          agreement herein.

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<PAGE>
     (d)  The Agent shall make reasonable efforts to assist the Company in
          obtaining performance by each purchaser whose offer to purchase Blocks
          has been solicited by the Agent and accepted by the Company. The Agent
          shall not have any liability to the Company if any such agency
          purchase is not consummated for any reason. If the Company shall
          default on its obligation to deliver Blocks to a purchaser whose offer
          it has accepted, the Company shall (i) hold the Agent harmless against
          any loss, claim or damage arising from or as a result of such default
          by the Company and (ii) notwithstanding such default, pay to such
          Agent any fee to which it would otherwise be entitled in connection
          with such sale.

2.   Purchases as Principal.

     (a)  All purchases of Shares, other than purchases of Blocks, unless
          otherwise expressly agreed, shall be purchased by the Agent as
          principal. In the absence of a separate written agreement, the Agent's
          commitment to purchase Shares as principal shall be deemed to have
          been made on the basis of the representations, warranties and
          covenants contained herein and shall be subject to the terms and
          conditions set forth herein.

     (b)  For purchases as principal (other than Blocks), the Company shall sell
          to the Agent, and the Agent agrees to purchase from the Company, the
          number of Shares determined in the manner and on the terms set forth
          below. The Agent intends to resell the Shares purchased under this
          Agreement in transactions and at prices related to the prevailing
          market price of the Common Stock or in such other manner as may be
          provided in the Prospectus and may engage in sales of Common Stock,
          including short sales, in advance of or on the Purchase Date for any
          Shares deliverable pursuant to a Purchase Notice.

3.   Delivery of Purchase Notices.

     (a)  The Company may exercise its right to sell Shares (including Blocks)
          hereunder by delivering (in accordance with Section 12 hereof) on any
          Exchange Business Day (as defined below) a written notice to the Agent
          of its election to sell Shares (each such notice, a "Purchase
          Notice"). Each Purchase Notice shall specify:

          (i)  whether such Shares shall be sold through the Agent acting as
               principal or whether the Company and the Agent have expressly
               agreed that the Company shall sell such shares to the Agent
               acting as agent;

          (ii) the number of Shares that the Company intends to sell (the
               "Specified Number of Shares"), which shall be no less than 5% and
               no more than 20% of the average daily trading volume in the
               Common Stock on the Exchange for the thirty (30) Exchange
               Business Days preceding the date of delivery of the Purchase
               Notice, except as otherwise agreed in writing by the Agent in its
               sole discretion;

          (iii) whether the Company will grant the Agent the right to elect to
               purchase additional Shares in accordance with subsection (c)
               below; and

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<PAGE>

          (iv) in the case of a purchase of Shares by the Agent acting as
               principal, whether the Company elects to give the Agent the
               option to increase the number of Shares to be sold by the Company
               and purchased by the Agent acting as principal on such Purchase
               Date.

               A Purchase Notice shall not set forth a Specified Number of
               Shares that, when added to the aggregate number of Shares
               previously purchased and to be purchased pursuant to pending
               Purchase Notices (if any) hereunder, results in a total that
               exceeds the Maximum Number of Shares. The Company shall have
               responsibility for maintaining records with respect to the
               aggregate principal amount of Shares sold, or for otherwise
               monitoring the availability of Shares for sale under the
               Registration Statement. The Company may deliver only one Purchase
               Notice with respect to any Purchase Date. A Purchase Notice
               conforming to the foregoing requirements, once given, shall be
               irrevocable, and the Company shall be obligated to sell the
               Specified Number of Shares (subject to increase pursuant to
               paragraph (c) below) and the Agent shall be obligated, subject to
               the satisfaction of the conditions set forth in this Agreement,
               to (x) in case of sales by the Agent acting as agent, use its
               reasonable best efforts to solicit offers for the Shares, and (y)
               in case of purchases by the Agent acting as principal, purchase
               such Shares in accordance with the Purchase Notice.

     (b)  The "Purchase Date" in respect of the Shares deliverable pursuant to
          any Purchase Notice shall be the Exchange Business Day next following
          the day on which such Purchase Notice is delivered; provided that if a
          Purchase Notice is delivered prior to 8:30 a.m. (New York time) on an
          Exchange Business Day, the Purchase Date in respect of such Shares
          shall be such date of delivery. For sales and purchases which the
          Agent undertakes as principal, the price per Share for the sale and
          purchase of any such Shares pursuant to this Agreement shall be equal
          to the volume weighted average price per share at which shares of the
          Common Stock traded on the Exchange during regular trading hours on
          the Purchase Date, as reported on the Nasdaq National Market System
          (the "Gross Sale Price"), less the Agent's commission of (i) 5 1/4% of
          the Gross Sale Price for all Shares sold and purchased as principal on
          such Purchase Date, if the Company shall have granted, and the Agent
          shall have exercised in whole or in part, an option pursuant to
          paragraph (c) below to increase the number of Shares sold and
          purchased as principal on such Purchase Date, or (ii) 6% of the Gross
          Sale Price, in any other case (the Gross Sale Price less the Agent's
          commission is referred to herein as the "Net Sale Price"). For sales
          and purchases of Blocks that the Agent undertakes on a principal
          basis, the price per Share and the commission shall be agreed upon
          between the Company and the Agent on the date of delivery of the
          Purchase Notice.

     (c)  If the Company shall have so specified in a Notice of Purchase, which
          relates to a sale to the Agent acting as principal, delivered in
          respect of a Purchase Date, the Agent will have the option to elect,
          by notice to the Company delivered not later than 4:30 p.m. (New York
          time) on such Purchase Date, to increase the number of
                                      -5-

          Shares to be sold by the Company and purchased by the Agent acting as
          principal on such Purchase Date, provided that such number of Shares
          to be sold by the Company shall not exceed two times the Specified
          Number of Shares; and provided further that such number of Shares to
          be sold by the Company, when added to the aggregate number of Shares
          previously purchased and to be purchased pursuant to pending Purchase
          Notices (if any) hereunder, shall not exceed the Maximum Number of
          Shares. The Specified Number of Shares to be sold by the Company on
          any Purchase Date, as it may be increased pursuant to this paragraph
          (c), is hereinafter referred to as the "Purchased Number of Shares" in
          respect of such Purchase Date.

     (d)  If the Purchased Number of Shares for any Purchase Date exceeds 50% of
          the total number of shares of Common Stock traded on the Exchange
          during regular trading hours on the Purchase Date, the Purchased
          Number shall be reduced to 50% of such total number of shares traded
          unless, in its sole discretion, the Agent waives this condition in
          writing as to any Purchase Date.

     (e)  As used herein:

          "Block" means, as more fully defined in Rule 10b-18 promulgated under
          the 1934 Act, a quantity of stock that either (i) has a purchase price
          of $200,000 or more; or (ii) is at least 5,000 shares and has a
          purchase price of at least $50,000; or (iii) is at least 20 round lots
          of the security and totals 150 percent or more of the trading volume
          for that security or, in the event that trading volume data are
          unavailable, is at least 20 round lots of the security and totals at
          least 1/10th of one percent (.001) of the outstanding shares of the
          security, exclusive of any shares owned by an affiliate; provided,
          however, that a block under subsection (i), (ii) and (iii) of this
          paragraph shall not include any amount that a broker or a dealer,
          acting as principal, has accumulated for the purpose of sale or resale
          to the issuer or to any affiliated purchaser of the issuer if the
          issuer or such affiliated purchaser knows or has reason to know that
          such amount was accumulated for such purpose, nor shall it include any
          amount that a broker or dealer has sold short to the issuer or to any
          affiliated purchaser of the issuer if the issuer or such affiliated
          purchaser knows or has reason to know that the sale was a short sale.

          "Exchange Business Day" means any day that is a trading day for the
          Exchange other than a day on which trading on the Exchange is
          scheduled to close prior to its regular weekday closing time,

          "Exchange" means the Nasdaq National Market System, and

     (f)  Payment of the purchase price for Shares sold by the Company on any
          Purchase Date pursuant to a Purchase Notice shall be made to the
          Company by federal funds wire transfer to account number ___________
          against delivery of such Shares to: (x) the accounts specified in
          writing by the Agent for sales made by the Agent acting as agent, or
          (y) the Agent through the facilities of the Depository Trust Company
          for purchase from the Company by the Agent acting as principal.

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<PAGE>

          Such payment and delivery shall be made at or about 10:00 a.m., local
          time in New York, New York, on the third Exchange Business Day
          following each Purchase Date (the "Closing Date"). If the Company
          fails for any reason to make timely delivery of such Shares, the
          Company shall indemnify the Agent and its successors and assigns and
          hold them harmless from and against any loss, damage, expense,
          liability or claim that the Agent may incur as a result of such
          failure.

     4. Representations and Warranties of the Company. The Company represents
and warrants to the Agent, on and as of (i) the date hereof, (ii) each date on
which the Company delivers a Purchase Notice to the Agent, (iii) each Purchase
Date, (iv) each Closing Date, and (v) each date on which the Registration
Statement or the Prospectus is amended or supplemented or there is filed by the
Company with the Commission any document incorporated by reference into the
Prospectus (other than any Current Report on Form 8-K relating exclusively to
the issuance of Shares under the Registration Statement)(each such date listed
in (i) through (v), a "Representation Date") that:

     (a)  the Company meets the requirements for use of Form S-3 under the Act;
          the Registration Statement (including any Rule 462(b) Registration
          Statement) has become effective under the Act and no stop order
          suspending the effectiveness of the Registration Statement (including
          any Rule 462(b) Registration Statement) has been issued under the Act
          and no proceedings for that purpose have been instituted or are
          pending or, to the Company's knowledge, are threatened by the
          Commission, and any request on the part of the Commission for
          additional information has been complied with; the Registration
          Statement (including any Rule 462(b) Registration Statement) and any
          amendments thereto (including the filing of the Company's most recent
          Annual Report on Form 10-K with the Commission (the "Annual Report on
          Form 10-K")) comply in all material respects with the requirements of
          the Act and do not contain an 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; each
          preliminary prospectus and 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 Act, complied when so
          filed in all material respects with the Act; each preliminary
          prospectus and the Prospectus delivered to the Agent for use in
          connection with the offering of Shares are identical to any
          electronically transmitted copies thereof filed with the Commission
          pursuant to EDGAR, except to the extent permitted by Regulation S-T;
          and neither the Prospectus nor any amendment or supplement thereto
          includes an untrue statement of a material fact 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; provided, however, that the representations and warranties
          in this subsection shall not apply to statements in or omissions from
          the Registration Statement or the Prospectus made in reliance upon and
          in conformity with information furnished to the Company in writing by
          the Agent expressly for use in the Registration Statement or the
          Prospectus;

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<PAGE>

     (b)  the documents incorporated or deemed to be incorporated by reference
          in the Prospectus, at the time they were or hereafter are filed with
          the Commission, complied and will comply in all material respects with
          the requirements of the 1934 Act and, when read together with the
          other information in the Prospectus, at the date of the Prospectus and
          at each Representation Date, did not and will not include an untrue
          statement of a material fact or omit 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;

     (c)  as of the date of this Agreement the Company has, and as of each
          Representation Date the Company will have, an authorized
          capitalization as set forth in the Registration Statement and the
          Prospectus; all of the issued and outstanding shares of capital stock
          of the Company and the Subsidiaries (as defined below), including the
          Common Stock, have been duly and validly authorized and issued and are
          fully paid and non-assessable, have been issued in compliance with all
          applicable laws (including, but not limited to, federal and state
          securities laws) and were not issued in violation of any preemptive
          right, resale right, right of first refusal or similar right;

     (d)  the Maximum Number of Shares is less than 10% of the aggregate market
          value of the Company's outstanding voting stock held by non-affiliates
          of the Company (calculated as of a date within 60 days prior to the
          date of the filing of the Registration Statement);

     (e)  except as disclosed in the Registration Statement, each of the Company
          and each subsidiary of the Company set forth on Schedule I hereto
          (each a "Subsidiary" and, collectively, the "Subsidiaries") has been
          duly incorporated and is validly existing as a corporation and is in
          good standing under the laws of its respective jurisdiction of
          incorporation with all requisite corporate power and authority to own,
          lease and operate its respective properties and to conduct its
          respective business as conducted and as proposed to be conducted as
          described in the Registration Statement and Prospectus;

     (f)  each of the Company and the Subsidiaries is duly qualified or
          registered to do business as a foreign corporation in good standing in
          each jurisdiction in which it conducts its respective business as
          conducted, and as proposed to be conducted as described in the
          Registration Statement and Prospectus, where the ownership or leasing
          of its properties or the conduct of its business requires such
          qualification, except where the failure to so qualify, individually or
          in the aggregate, would not have a material adverse effect on the
          business, prospects, properties, financial condition or results of
          operation of the Company and the Subsidiaries, taken as a whole (a
          "Material Adverse Effect");

     (g)  the Company has no significant subsidiaries (as defined in Rule 1-02
          of Regulation S-X under the Act) other than the Subsidiaries; other
          than the Subsidiaries the Company does not own, directly or
          indirectly, any shares of stock or any other

                                      -8-
<PAGE>

          equity or long-term debt securities of any corporation or have any
          equity interest in any firm, partnership, joint venture, association
          or other entity;

     (h)  complete and correct copies of the certificates of incorporation and
          of the bylaws of the Company and the Subsidiaries and all amendments
          thereto have been delivered to you or included in the Registration
          Statement, and except as set forth in the Registration Statement no
          changes therein will be made during the term of this agreement;

     (i)  except as disclosed in the Registration Statement, all of the
          outstanding shares of capital stock of each of the Subsidiaries have
          been duly authorized and validly issued, are fully paid and
          non-assessable and (except as otherwise described in this Section
          4(i)) are owned by the Company subject to no security interest, other
          encumbrance or adverse claims; no options, warrants or other rights to
          purchase, agreements or other obligations to issue or other rights to
          convert any obligation into shares of capital stock or ownership
          interests in the Subsidiaries are outstanding;

     (j)  except as disclosed in the Registration Statement, the Company and
          each of the Subsidiaries are in compliance in all material respects
          with all applicable laws, orders, rules, regulations, directives,
          decrees and judgments;

     (k)  except as disclosed in the Registration Statement, neither the Company
          nor any of the Subsidiaries is in breach of, or in default (nor has
          any event occurred which with notice, lapse of time, or both would
          result in any breach of, or constitute a default under), under (a) its
          respective certificate of incorporation, charter or by-laws or (b) in
          the performance or observance of any obligation, agreement, covenant
          or condition contained in any license, indenture, mortgage, deed of
          trust, bank loan or credit agreement or other evidence of
          indebtedness, or any lease, contract or other agreement or instrument
          to which the Company or any of the Subsidiaries is a party or by which
          any of them or any of their properties is bound, except in the case of
          clause (b), for such breaches or defaults as would not reasonably be
          expected to have a Material Adverse Effect, and the execution,
          delivery and performance of this Agreement, the issuance and sale of
          the Shares and the consummation of the transactions contemplated
          hereby will not conflict with, or result in any breach of or
          constitute a default under (nor constitute any event which with
          notice, lapse of time, or both would result in any breach of, or
          constitute a default under) (i) any provision of the articles of
          incorporation, charter or by-laws of the Company or any of the
          Subsidiaries, or (ii) any provision of any license, indenture,
          mortgage, deed of trust, bank loan or credit agreement or other
          evidence of indebtedness, or any lease, contract or other agreement or
          instrument to which the Company or any of the Subsidiaries is a party
          or by which any of them or their respective properties may be bound or
          affected, or (iii) any federal, state, local or foreign law,
          regulation or rule or any decree, judgment or order applicable to the
          Company or any of the Subsidiaries, except in the case of clauses (ii)
          and (iii) for such conflicts, breaches, or defaults, individually or
          in the aggregate, as would not reasonably be expected to have a
          Material Adverse Effect;

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<PAGE>

     (l)  the Company has full legal right, power and authority to enter into
          and perform this Agreement and to consummate the transactions
          contemplated herein; this Agreement has been duly authorized, executed
          and delivered by the Company and is a legal, valid and binding
          agreement of the Company enforceable in accordance with its terms,
          except (i) as may be limited by bankruptcy, insolvency,
          reorganization, moratorium or similar laws affecting creditors' rights
          generally, or (ii) as any rights to indemnity or contribution
          hereunder may be limited by federal and state securities laws and
          public policy considerations;

     (m)  the capital stock of the Company, including the Shares, conforms in
          all material respects to the description thereof contained in the
          Registration Statement and Prospectus, and the certificates for the
          Shares (to the extent such Shares are certificated) are in due and
          proper form;

     (n)  the issuance and sale of the Shares through or to the Agent hereunder
          have been duly authorized by the Company; when issued and delivered
          against payment therefor as provided in this Agreement, the Shares
          will be validly issued, fully paid and non-assessable and the issuance
          of the Shares will not be subject to any preemptive or similar rights;
          no person or entity holds a right to require or participate in the
          registration under the Act of the Shares pursuant to the Registration
          Statement; no person or entity has a right of participation or first
          refusal with respect to the sale of the Shares by the Company;

     (o)  there are no contracts, agreements or understandings between the
          Company or its Subsidiaries and any person or entity granting such
          person or entity the right, contractual or otherwise, to cause the
          Company to issue to it, or register pursuant to the Act, any
          securities or shares of capital stock of the Company upon the issue
          and sale of the Shares to the Agent hereunder, or to require the
          Company to include such securities with the Shares registered pursuant
          to the Registration Statement, nor does any person have preemptive
          rights, co-sale rights, rights of first refusal or other rights to
          purchase any of the Shares other than those that have been expressly
          waived before the date hereof;

     (p)  the form of certificates evidencing the Shares (to the extent such
          Shares are certificated) complies with all applicable legal
          requirements and, in all material respects, with all applicable
          requirements of the charter and bylaws of the Company and the
          requirements of the NASD;

     (q)  no approval, authorization, consent or order of or filing with any
          federal, state or local governmental or regulatory commission, board,
          body, authority or agency is required in connection with (i) the
          execution, delivery and performance by the Company of this Agreement
          and the consummation of the transactions contemplated hereby or (ii)
          the sale and delivery of the Shares, other than (x) such as have been
          obtained, or will have been obtained on the relevant Closing Date
          under the Act or the 1934 Act, (y) such approvals as have been
          obtained in connection with the approval of the listing of the Shares
          on the Nasdaq National Market System and (z) any necessary
          qualification under the securities or blue sky

                                      -10-

<PAGE>

          laws of the various jurisdictions in which the Shares are being
          offered by the Agent;

     (r)  Ernst & Young LLP, whose report on the consolidated financial
          statements of the Company and the Subsidiaries is filed with the
          Commission as part of the Registration Statement and Prospectus, are
          and were during the periods covered by their reports independent
          public accountants as required by the Act;

     (s)  each of the Company and the Subsidiaries has all necessary licenses,
          authorizations, consents and approvals and has made all necessary
          filings required under any federal, state, local or foreign law,
          regulation or rule, and has obtained all necessary authorizations,
          consents and approvals from other persons, in order to conduct its
          respective business, unless the failure to possess such licenses,
          authorizations, consents and other governmental or regulatory
          authorizations and approvals, individually or in the aggregate, could
          not reasonably be expected to have Material Adverse Effect; neither
          the Company nor any of the Subsidiaries is in violation of, in default
          under or has received any notice regarding a possible violation,
          default or revocation of any such license, authorization, consent or
          approval or any federal, state, local or foreign law, regulation or
          rule or any decree, order or judgment applicable to the Company or any
          of the Subsidiaries the effect of which could reasonably be expected
          to have a Material Adverse Effect;

     (t)  the Prospectus in paper format delivered to the Agent for use in
          connection with this offering will be identical in all material
          respects to the version of the Prospectus created to be transmitted to
          the Commission for filing via EDGAR, except to the extent permitted by
          Regulation S-T;

     (u)  all legal or governmental proceedings, contracts, leases or documents
          of a character required to be described in the Registration Statement
          or the Prospectus or to be filed as an exhibit to the Registration
          Statement have been so described or filed as required;

     (v)  except as disclosed in the Registration Statement, there are no legal
          or governmental proceedings pending or threatened to which the Company
          or any of the Subsidiaries or any of their respective officers is a
          party or of which any of their respective properties is subject at law
          or in equity, or before or by any federal, state, local or foreign
          governmental or regulatory commission, which, if determined adversely
          to the Company or any of its Subsidiaries, could result in a judgment,
          decree or order which could reasonably be expected to have a Material
          Adverse Effect or prevent consummation of the transactions
          contemplated hereby;

     (w)  the consolidated financial statements of the Company and the
          Subsidiaries included in the Registration Statement and the Prospectus
          present fairly in all material respects the consolidated financial
          position of the Company and the Subsidiaries as of the dates indicated
          and the consolidated results of operations and cash flows of the
          Company and the Subsidiaries for the periods specified; such financial
          statements have been prepared in conformity with generally accepted

                                      -11-
<PAGE>

          accounting principles as applied in the United States and on a
          consistent basis during the periods involved and in accordance with
          Regulation S-X promulgated by the Commission; the financial statement
          schedules included or incorporated by reference in the Registration
          Statement and the Prospectus fairly present in all material respects
          the information required to be shown therein; no other financial
          statements or schedules are required by Form S-3 or otherwise to be
          included in the Registration Statement or Prospectus; any pro forma
          financial statements and other pro forma financial information
          included in the Registration Statement and the Prospectus present
          fairly the information shown therein, have been prepared in accordance
          with the Commission's rules and guidelines for pro forma financial
          statements, have been properly compiled on the pro forma bases set
          forth therein and, in the opinion of the Company, the assumptions used
          in the preparation thereof are reasonable and the adjustments used
          therein are appropriate to reflect the transaction or circumstances
          referred to therein;

     (x)  subsequent to the respective dates as of which information is given in
          the Registration Statement and the Prospectus, there has not been (i)
          any material adverse change, or any development involving a
          prospective material adverse change, in the business, prospects,
          properties or assets described or referred to in the Registration
          Statement, or the results of operations, condition (financial or
          otherwise), business or operations of the Company and the
          Subsidiaries, whether or not arising in the ordinary course of
          business, or (ii) any transaction which is material to the Company or
          the Subsidiaries, planned or entered into by the Company or any of the
          Subsidiaries, or (iii) any obligation, direct or contingent, which is
          material to the Company and the Subsidiaries, incurred by the Company
          or the Subsidiaries, except obligations incurred in the ordinary
          course of business, or (iv) any change in the capital stock or
          outstanding indebtedness of the Company or the Subsidiaries, or (v)
          any dividend or distribution of any kind declared, paid or made on the
          capital stock of the Company. Neither the Company nor the Subsidiaries
          has any material contingent obligation which is not disclosed in the
          Registration Statement;

     (y)  the Company has filed in a timely manner all reports required to be
          filed pursuant to Sections 13, 14, 15(d) of the 1934 Act during the
          preceding twelve calendar months and if during such period the Company
          has relied on Rule 12b-25(b) under the 1934 Act ("Rule 12b-25(b)")
          with respect to a report or a portion of a report, that report or
          portion of a report has actually been filed within the time period
          prescribed by Rule 12b-25(b);

     (z)  the Company is not and, after giving effect to the offering and sale
          of the Shares, will not be 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 (the "Investment
          Company Act");

     (aa) except as disclosed in the Prospectus or on Schedule 4(aa), there are
          no outstanding (i) securities or obligations of the Company or any of
          its Subsidiaries convertible into or exchangeable for any capital
          stock of the Company or any such Subsidiary, or (ii) warrants, rights
          or options to subscribe for or purchase from the Company or any such

                                      -12-


<PAGE>

          Subsidiary any such capital stock or any such convertible or
          exchangeable securities or obligations, or (iii) obligations of the
          Company or any such Subsidiary to issue any shares of capital stock,
          any such convertible or exchangeable securities or obligation, or any
          such warrants, rights or options;

     (bb) each of the Company, the Subsidiaries, and each of their respective
          officers, directors and controlling persons has not taken, and will
          not take, directly or indirectly, any action which is designed to or
          which has constituted or which might reasonably be expected to cause
          or result in stabilization or manipulation of the price of any
          security of the Company to facilitate the sale or resale of the
          Shares;

     (cc) the Company (i) is not required to register as a "broker" or "dealer"
          in accordance with the provisions of the 1934 Act or the rules and
          regulations thereunder, and (ii) directly, or indirectly through one
          or more intermediaries, does not control any member firm of the NASD;

     (dd) the Company has not relied upon the Agent or legal counsel for the
          Agent for any legal, tax or accounting advice in connection with the
          offering and sale of the Shares;

     (ee) any certificate signed by any officer of the Company or any Subsidiary
          delivered to the Agent or to counsel for the Agent pursuant to or in
          connection with this Agreement shall be deemed a representation and
          warranty by the Company to the Agent as to the matters covered
          thereby;

     (ff) to the Company's knowledge, all agreements between the Company or any
          of the Subsidiaries and third parties expressly referenced in the
          Prospectus are legal, valid and binding obligations of the Company or
          one or more of the Subsidiaries, enforceable in accordance with their
          respective terms, except to the extent enforceability may be limited
          by bankruptcy, insolvency, reorganization, moratorium or similar laws
          affecting creditors' rights generally and by general principles of
          equity;

     (gg) no relationship, direct or indirect, exists between or among the
          Company or any of the Subsidiaries, on the one hand, and the
          directors, officers, stockholders, customers or suppliers of the
          Company or any of the Subsidiaries, on the other hand, which is
          required by the Act to be described in the Registration Statement and
          the Prospectus that is not so described;

     (hh) with such exceptions as could not reasonably be expected to have a
          Material Adverse Effect on the Company and the Subsidiaries, taken as
          a whole, the Company and the Subsidiaries have good and marketable
          title in fee simple to all real property, if any, and good title to
          all personal property owned by them, in each case free and clear of
          all liens, security interests, pledges, charges, encumbrances,
          mortgages and defects, except such as are disclosed in the Prospectus
          or such as do not materially and adversely affect the value of such
          property and do not interfere

                                      -13-
<PAGE>

          with the use made or proposed to be made of such property by the
          Company and the Subsidiaries; and any real property and buildings held
          under lease by the Company or any Subsidiary are held under valid,
          existing and enforceable leases, with such exceptions as are disclosed
          in the Prospectus or are not material and do not interfere with the
          use made or proposed to be made of such property and buildings by the
          Company or such Subsidiary;

     (ii) the Company and the Subsidiaries have ownership or license or legal
          right to use all material patent, copyright, trade secret and
          trademark rights known by it to be necessary to the conduct of the
          business of the Company and the Subsidiaries as now conducted
          (collectively, "Intellectual Property") other than Intellectual
          Property generally available on commercial terms from other sources;

     (jj) all material licenses or other material agreements under which (i) the
          Company and the Subsidiaries are granted rights in Intellectual
          Property, other than Intellectual Property generally available on
          commercial terms from other sources, and (ii) the Company or any
          Subsidiary has granted rights to others in Intellectual Property owned
          or licensed by the Company or the Subsidiaries, are in full force and
          effect and there is no material default by the Company or any
          Subsidiary or, to the Company's knowledge, any other party thereto;

     (kk) each of the Company and the Subsidiaries have taken all reasonable
          steps required in accordance with sound business practice and business
          judgment to establish and preserve its ownership of all material
          copyright, trade secret and other proprietary rights with respect to
          its products and technology;

     (ll) the present business, activities and products of the Company and the
          Subsidiaries do not infringe any Intellectual Property of any other
          person, except where such infringement would not, individually or in
          the aggregate, have a Material Adverse Effect on the Company. Except
          as described in documents filed with the Commission, to the Company's
          knowledge, no proceeding charging the Company or any Subsidiary with
          infringement of any adversely held Intellectual Property has been
          filed; the Company and the Subsidiaries are not making unauthorized
          use of any confidential information or trade secrets obtained by the
          Company or its Subsidiaries from any other person; the activities of
          each of the Company or the Subsidiaries or any of its employees on
          behalf of the Company or any Subsidiary do not violate any agreements
          or arrangements known to the Company or any Subsidiary which any such
          employees have with other persons, if any;

     (mm) the Company and each of its Subsidiaries maintain a system of internal
          accounting controls sufficient to provide reasonable assurance that
          (i) transactions are executed in accordance with management's general
          or specific authorizations; (ii) transactions are recorded as
          necessary to permit preparation of financial statements in conformity
          with generally accepted accounting principles as applied in the United
          States and to maintain asset accountability; (iii) access to assets is
          permitted only in accordance with management's general or specific
          authorization; and (iv) the recorded accountability for assets is
          compared with the existing assets

                                      -14-
<PAGE>

          at reasonable intervals and appropriate action is taken with respect
          to any differences;

     (nn) each of the Company and the Subsidiaries have filed on a timely basis
          all material federal, state, local and foreign income and franchise
          tax returns required to be filed through the date hereof and have paid
          all taxes shown as due thereon; and no tax deficiency has been
          asserted against any such entity, nor does any such entity know of any
          tax deficiency which is likely to be asserted against any such entity
          which if, determined adversely to any such entity, could have a
          Material Adverse Effect; all tax liabilities are adequately provided
          for on the respective books of such entities;

     (oo) neither the Company nor any of the Subsidiaries nor, to the best of
          the Company's knowledge, any agent, officer or director purporting to
          act on behalf of the Company or any of the Subsidiaries has at any
          time; (i) made any contributions to any candidate for political
          office, or failed to disclose fully any such contributions, in
          violation of law, or (ii) made any payment to any state, federal or
          foreign governmental officer or official, or other person charged with
          similar public or quasi-public duties, other than payments required or
          allowed by applicable law, or (iii) received or retained any funds in
          violation of law or of a character required to be disclosed in the
          Prospectus;

     (pp) the Shares have been approved for listing, upon official notice of
          issuance, on the Nasdaq National Market System;

     (qq) in connection with this offering, the Company has not offered and will
          not offer shares of its Common Stock or any other securities
          convertible into or exchangeable or exercisable for shares of Common
          Stock in a manner in violation of the Act; the Company has not
          distributed and will not distribute any offering material in
          connection with the offer and sale of the Shares, other than the
          Prospectus, Registration Statement and other materials permitted by
          the Act; and

     (rr) the Company has not incurred any liability for any finder's fees or
          similar payments in connection with the transactions herein
          contemplated.

5.   Certain Covenants of the Company.  The Company hereby agrees with the
Agent:


     (a)  before amending or supplementing the Registration Statement or the
          Prospectus, or, during any period of time in which a Prospectus
          relating to the Shares is required to be delivered under the Act, to
          furnish to the Agent a copy of each such proposed amendment or
          supplement before filing any such amendment or supplement with the
          Commission;

     (b)  to make no amendment or supplement to the Registration Statement or
          the Prospectus which shall have been disapproved by the Agent by
          notice in writing to the Company after notice thereof and reasonable
          opportunity to review and comment thereon;

                                      -15-
<PAGE>

     (c)  to prepare, with respect to any Shares sold by the Company to the
          Agent pursuant to this Agreement, a Pricing Supplement with respect to
          such Shares in a form previously approved by the Agent and to file
          such Pricing Supplement pursuant to Rule 424(b) under the Act not
          later than the close of business of the Commission on the third
          business day after any Purchase Date on which an aggregate of __% or
          more of the Shares were sold, and provide each such Pricing Supplement
          to the Agent at the same time;

     (d)  to file promptly all reports and any definitive proxy or information
          statements required to be filed by the Company with the Commission
          pursuant to Sections 13(a), 13(c), 14 or 15(d) of the 1934 Act for so
          long as the delivery of a Prospectus is required in connection with
          the offering or sale of the Shares, and during such same period to
          advise the Agent, promptly after the Company receives notice thereof,
          of the time when any amendment to the Registration Statement has been
          filed or has become effective or any supplement to the Prospectus or
          any amended Prospectus has been filed with the Commission, or the
          issuance by the Commission of any stop order or of any order
          preventing or suspending the use of any prospectus relating to the
          Shares, or the suspension of the qualification of the Shares for
          offering or sale in any jurisdiction, of the initiation or threatening
          of any proceeding for any such purpose, or of any request by the
          Commission for the amendment or supplementation of the Registration
          Statement or Prospectus or for additional information; and

     (e)  in the event of the issuance of any such stop order or of any such
          order preventing or suspending the use of any such prospectus or
          suspending any such qualification, to use promptly its reasonable best
          efforts to obtain its withdrawal;

     (f)  to furnish such information as may be required and otherwise to
          cooperate in qualifying the Shares for offering and sale under the
          securities or blue sky laws of such states as you may reasonably
          designate and to maintain such qualifications in effect so long as
          required for the distribution of the Shares; provided that the Company
          shall not be required to qualify as a foreign corporation, become a
          dealer of securities, or become subject to taxation in, or to consent
          to the service of process under the laws of any such state (except
          service of process with respect to the offering and sale of the
          Shares); and to promptly advise you of the receipt by the Company of
          any notification with respect to the suspension of the qualification
          of the Shares for sale in any jurisdiction or the initiation of any
          proceeding for such purpose;

     (g)  to make available to the Agent in Stamford, Connecticut, as soon as
          practicable after the Registration Statement becomes effective, and
          thereafter from time to time to furnish to the Agent, as many copies
          of the Prospectus (or of the Prospectus as amended or supplemented if
          the Company shall have made any amendments or supplements thereto
          after the effective date of the Registration Statement) as the Agent
          may reasonably request for the purposes contemplated by the Act; and
          for so long as this agreement is in effect, the Company will prepare
          and file promptly, subject to Section 5(b) hereof, such amendment or
          amendments

                                      -16-
<PAGE>

          to the Registration Statement and the Prospectus as may be necessary
          to comply with the requirements of Section 10(a)(3) of the Act;

     (h)  to furnish to you for a period of five years from the date of this
          Agreement (i) copies of any reports or other communications which the
          Company shall send to its stockholders or shall from time to time
          publish or publicly disseminate, (ii) copies of all annual, quarterly
          and current reports filed with the Commission on Forms 10-K, 10-Q and
          8-K, or such other similar form as may be designated by the
          Commission, (iii) copies of documents or reports filed with any
          national securities exchange on which any class of securities of the
          Company is listed, and (iv) such other information as you may
          reasonably request regarding the Company or the Subsidiaries, in each
          case as soon as such reports, communications, documents or information
          becomes available;

     (i)  if at any time during the term of this Agreement any event shall occur
          or condition exist as a result of which it is necessary, in the
          reasonable opinion of counsel for the Agent or counsel for the
          Company, to further amend or supplement the Prospectus in order that
          the Prospectus will not include an untrue statement of a material fact
          or omit to state any material fact necessary in order to make the
          statements therein not misleading in light of the circumstances
          existing at the time the Prospectus is delivered to a purchaser, or if
          it shall be necessary, in the reasonable opinion of either such
          counsel, to amend or supplement the Registration Statement or the
          Prospectus in order to comply with the requirements of the Act,
          immediate notice shall be given, and confirmed in writing, to the
          Agent to cease the solicitation of offers to purchase the Shares in
          the Agent's capacity as agent and to cease sales of any Shares the
          Agent may then own as principal, and the Company will promptly prepare
          and file with the Commission such amendment or supplement, whether by
          filing documents pursuant to the Act, the 1934 Act or otherwise, as
          may be necessary to correct such untrue statement or omission or to
          make the Registration Statement and Prospectus comply with such
          requirements;

     (j)  to generally make available to its security holders as soon as
          practicable, but not later than 90 days after the close of the period
          covered thereby, an earnings statement (in form complying with the
          provisions of Section 11(a) under the Act) covering each twelve-month
          period beginning, in each case, not later than the first day of the
          Company's fiscal quarter next following the "effective date" (as
          defined in such Rule 158) of the Registration Statement with respect
          to each sale of Shares;

     (k)  to furnish to you two signed copies of the Registration Statement, as
          initially filed with the Commission, and of all amendments thereto,
          including all exhibits thereto and all documents incorporated by
          reference therein;

     (l)  to apply the net proceeds from the sale of the Shares in the manner
          set forth under the caption "Use of Proceeds" in the Prospectus;

     (m)  to pay all costs, expenses, fees and taxes in connection with (i) the
          preparation and filing of the Registration Statement, each Preliminary
          Prospectus, the Prospectus,

                                      -17-
<PAGE>

          and any amendments or supplements thereto, and the printing and
          furnishing of copies of each thereof to the Agent and to dealers
          (including costs of mailing and shipment), (ii) the registration,
          issue, sale and delivery of the Shares, (iii) the producing, word
          processing and/or printing of this Agreement, any powers of Attorney
          and any closing documents (including compilations thereof) and the
          reproduction and/or printing and furnishing of copies of each thereof
          to the Agent (including costs of mailing and shipment), (iv) the
          qualification of the Shares for offering and sale under state laws and
          the determination of their eligibility for investment under state law
          as aforesaid (including the legal fees and filing fees and other
          disbursements of counsel for the Agent) and the printing and
          furnishing of copies of any blue sky surveys or legal investment
          surveys to the Agent, (v) the listing of the Shares on the Exchange
          and any registration thereof under the 1934 Act, (vi) any filing for
          review of the public offering of the Shares by the NASD, including the
          fees and disbursements of counsel to the Agent in connection
          therewith, (vii) all other fees and disbursements of counsel to the
          Company and counsel to the Agent, and (viii) the performance of the
          Company's other obligations hereunder; provided that the Agent shall
          be responsible for any transfer taxes on resale of Shares by it;

     (n)  to furnish to you, before filing with the Commission subsequent to the
          effective date of the Registration Statement and during the period
          referred to in paragraph (g) above, a copy of any document proposed to
          be filed pursuant to Section 13, 14 or 15(d) of the 1934 Act;

     (o)  to use its reasonable best efforts to cause the Shares to be listed on
          the Exchange; and

     (p)  to use its best efforts to satisfy, or cause to be satisfied, the
          conditions set forth below in Section 6 on or in respect of each
          Closing Date hereunder.

     6. Execution of Agreement. The Agent's obligation to execute this Agreement
shall be subject to the satisfaction of the following conditions in connection
with and on the intended date of the execution of this Agreement:

     (a)  the Company shall have delivered to the Agent:

          (i)  an officer's certificate signed by two of its executive officers
               certifying as to the matters set forth in Exhibit A hereto;

          (ii) an opinion of White & Case LLP, counsel for the Company,
               addressed to the Agent and dated the date of this Agreement, in
               the form of Exhibit B hereto, with only such departures from such
               form as Stroock & Stroock & Lavan LLP, counsel for the Agent,
               shall have approved;

          (iii) an intellectual property opinion of White & Case LLP, addressed
               to the Agent and dated the date of this Agreement, in the form of
               Exhibit C hereto, with only

                                      -18-
<PAGE>

          such departures from such form as Stroock & Stroock & Lavan LLP,
          counsel for the Agent, shall have approved;

          (iv) a letter of Ernst & Young LLP dated the date of this Agreement
               and addressed to the Agent, in substantially the form set forth
               in Exhibit D hereto;

          (v)  evidence reasonably satisfactory to the Agent and its counsel
               that the Registration Statement has become effective;

          (vi) evidence reasonably satisfactory to the Agent and its counsel
               that the Shares have been approved for listing on the Exchange,
               subject only to notice of issuance at or before the time of
               purchase on the relevant Purchase Date; and

          (vii) such other documents as the Agent shall reasonably request; and

     (b)  The Agent shall have received the favorable opinion of Stroock &
          Stroock & Lavan LLP as to the matters set forth in Exhibit E hereto.

     7. Additional Covenants of the Company. The Company further covenants and
agrees with the Agent as follows:

     (a)  Each delivery of a Purchase Notice by the Company to the Agent shall
          be deemed to be an affirmation that the representations and warranties
          of the Company herein contained and contained in any certificate
          delivered to the Agent pursuant hereto are true and correct at the
          time of such delivery, and an undertaking that such representations
          and warranties will be true and correct at the time of the
          consummation of the purchase by the Agent, and at the time of delivery
          to the Agent of Shares pursuant to the Purchase Notice, as though made
          at and as of each such time (it being understood that such
          representations and warranties shall relate to the Registration
          Statement and Prospectus as amended and supplemented to the time of
          such Purchase Notice);

     (b)  Each time that the Registration Statement or the Prospectus shall be
          amended or supplemented (including by the filing of any document
          incorporated by reference therein, but excluding any prospectus
          supplement relating solely to the offering of Shares pursuant to a
          Purchase Notice), the Company shall furnish or cause to be furnished
          to the Agent forthwith a certificate, dated the date of filing with
          the Commission or the date of effectiveness of such amendment or
          supplement, as applicable, in form satisfactory to the Agent, to the
          effect that the statements contained in the certificate referred to in
          Section 6(a)(i) hereof are true and correct in all material respects
          at the time of the filing or effectiveness of such amendment or
          supplement, as applicable, as though made at and as of such time
          (except that such statements shall be deemed to relate to the
          Registration Statement and the Prospectus as amended and supplemented
          to such time) or, in lieu of such certificate, a certificate of the
          same tenor as the certificate referred to Section 6(a)(i) hereof,
          modified as necessary to relate to the Registration Statement and the
          Prospectus as amended and supplemented to the time of delivery of such

                                      -19-
<PAGE>

          certificate. Any such certificate shall also include a certification
          that there has been no material adverse change in the condition,
          financial or otherwise, or in the earnings, business affairs or
          business prospects of the Company and its subsidiaries considered as
          one enterprise since the date of the last such certificate previously
          delivered to the Agent;

     (c)  Each time that the Registration Statement or the Prospectus shall be
          amended or supplemented (including by the filing of any document
          incorporated by reference therein, but excluding any prospectus
          supplement relating solely to the offering of Shares pursuant to a
          Purchase Notice), the Company shall furnish or cause to be furnished
          forthwith to the Agent and to counsel for the Agent the written
          opinion of White & Case LLP, or other counsel satisfactory to the
          Agent, dated the date of filing with the Commission or the date of
          effectiveness of such amendment or supplement, as applicable, in form
          and substance satisfactory to the Agent, of the same tenor as the
          opinion referred to in Section 6(a)(ii) hereof, but modified as
          necessary to relate to the Registration Statement and the Prospectus
          as amended and supplemented to the time of delivery of such opinion
          or, in lieu of such opinion, counsel last furnishing such opinion to
          the Agent shall furnish the Agent with a letter substantially to the
          effect that the Agent may rely on such last opinion to the same extent
          as though it was dated the date of such letter authorizing reliance
          (except that statements in such last opinion shall be deemed to relate
          to the Registration Statement and the Prospectus as amended and
          supplemented to the time of delivery of such letter authorizing
          reliance);

     (d)  Each time that the Registration Statement or the Prospectus shall be
          amended or supplemented to include additional financial information
          (including by the filing of any document incorporated by reference
          therein), the Company shall cause Ernst & Young LLP immediately to
          furnish to the Agent a letter, dated the date of filing with the
          Commission or the date of effectiveness of such amendment or
          supplement, as applicable, of the same tenor as the letter referred to
          in Section 6(a)(iii) hereof, but modified to relate to the
          Registration Statement and Prospectus as amended and supplemented to
          the date of such letter; and

     (e)  Prior to the date of this Agreement (i) no stop order suspending the
          effectiveness of the Registration Statement or any post-effective
          amendment thereto, and no order directed at any document incorporated
          by reference therein and no order preventing or suspending the use of
          any Prospectus will have been issued by the Commission, and no
          suspension of the qualification of the Shares for offering or sale in
          any jurisdiction, or of the initiation or threatening of any
          proceedings for any of such purposes, will have occurred; and (ii) the
          Registration Statement and the Prospectus shall not contain an untrue
          statement of material fact or omit to state a material fact required
          to be stated therein or necessary to make the statements therein, in
          the light of the circumstances under which they were made, not
          misleading.

     8. Conditions of Agent's Obligation to Purchase Shares. The Company's right
to deliver a Purchase Notice and the Agent's obligation to, as the case may be,
solicit purchases on an

                                      -20-
<PAGE>

agency basis for, or purchase, the Shares pursuant to a Purchase Notice shall be
subject to the satisfaction of the following conditions at the time of delivery
of the Purchase Notice, the time of the commencement of trading on the Exchange
on the Purchase Date and at the time of closing on the Closing Date:

     (a)  the representations and warranties on the part of the Company herein
          contained or contained in any certificate of an officer or officers of
          the Company delivered pursuant to the provisions hereof shall be true
          and correct in all material respects;

     (b)  the Company shall have performed and observed its covenants and other
          obligations hereunder in all material respects;

     (c)  from the date of delivery of the Purchase Notice until the Closing
          Date, trading in the Common Stock on the Exchange shall not have been
          suspended;

     (d)  the Shares to be issued pursuant to the Purchase Notice shall have
          been approved for listing on the Exchange, subject only to notice of
          issuance;

     (e)  the Company shall furnish evidence reasonably satisfactory to the
          Agent and its counsel that the Registration Statement has become
          effective;

     (f)  no amendment or supplement to the Registration Statement or Prospectus
          shall have been filed to which the Agent shall have objected in
          writing; and

     (g)  the NASD shall not have raised any objections with respect to the
          fairness and reasonableness of the underwriting terms and
          arrangements.

     9. Termination by Agent. The obligations of the Agent hereunder shall be
subject to termination at any time in the sole and absolute discretion of the
Agent, (i) if any of the conditions specified in Section 6 shall not have been
fulfilled when and as required by this Agreement to be fulfilled, or (ii) if
there has been since the respective dates as of which information is given in
the Registration Statement, any material adverse change, or any development
involving a prospective material adverse change, in or affecting the assets,
operations, business or condition (financial or otherwise) of the Company,
whether or not arising in the ordinary course of business, or (iii) if there has
since the date hereof occurred an outbreak or escalation of hostilities or other
national or international calamity or crisis or change in economic, political or
other conditions the effect of which on the financial markets of the United
States is such as to make it, in the judgment of the Agent, impracticable to
market or deliver the Shares or enforce contracts for the sale of the Shares, or
(iv) if trading in any securities of the Company has been suspended by the
Commission or by the NASD or if trading generally on the Nasdaq National Market
System has been suspended (including automatic halt in trading pursuant to
market-decline triggers other than those in which solely program trading is
temporarily halted), or limitations on prices for trading (other than
limitations on hours or numbers of days of trading) have been fixed, or maximum
ranges for prices for securities have been required, by such exchange or the
NASD or by order of the Commission or any other governmental authority, or (v)
if there has been any downgrading in the rating of any of the Company's debt
securities or preferred stock by any "nationally recognized statistical rating

                                      -21-
<PAGE>

organization" (as defined for purposes of Rule 436(g) under the Securities Act),
or (vi) if any federal or state statute, regulation, rule or order of any court
or other governmental authority has been enacted, published, decreed or
otherwise promulgated which in the reasonable opinion of the Agent has a
Material Adverse Effect or will have a Material Adverse Effect on the assets,
operations, business or condition (financial or otherwise) of the Company, or
(vii) if any action has been taken by any federal, state or local government or
agency in respect of its monetary or fiscal affairs which in the reasonable
opinion of the Agent has a Material Adverse Effect on the securities markets in
the United States, or (viii) if any other material adverse change to the assets,
operations, business or condition (financial or otherwise) of the Company has
occurred, and in the case of any of the events specified in clauses (i) through
(viii), such event, singly or together with any other such events, makes it, in
the judgment of the Agent, impracticable or inadvisable to market or deliver the
Shares on the terms and in the manner contemplated in the Prospectus.

     If the Agent elects to terminate this Agreement as provided in this Section
9, the Company shall be notified promptly by telephone, promptly confirmed by
facsimile. If a Purchase Notice is pending at the time of termination, the Agent
may declare such Purchase Notice void or may require the Company to complete the
sale of Shares as specified in the Purchase Notice, at the Agent's sole
discretion.

     If the solicitation of purchases on an agency basis or purchase by the
Agent as principal of the Shares, as contemplated by this Agreement, is not
carried out by the Agent for any reason permitted under this Agreement or if
such sale is not carried out because the Company shall be unable to comply in
all material respects with any of the terms of this Agreement, the Company shall
not be under any obligation or liability under this Agreement (except to the
extent provided in Sections 5(m) and 11 hereof) and the Agent shall be under no
obligation or liability to the Company under this Agreement (except to the
extent provided in Section 11 hereof) or to one another hereunder.

     10. Termination by Company. Subject to Sections 8 and 9, if the Agent
defaults in its obligation to consummate a purchase of Shares to be purchased by
it hereunder (otherwise than for a reason sufficient to justify the termination
of this Agreement under the provisions of Section 9 hereof) and does not cure
such default within five Exchange Business Days, the Company may terminate this
Agreement by notice to the Agent.

     11. Indemnity and Contribution.

     (a)  The Company agrees to indemnify, defend and hold harmless the Agent,
          its directors and officers and any person who controls the Agent
          within the meaning of Section 15 of the Act or Section 20 of the 1934
          Act, and the successors and assigns of all of the foregoing persons
          from and against any loss, damage, expense, liability or claim
          (including the reasonable cost of investigation) which, jointly or
          severally, the Agent or any such person may incur under the Act, the
          1934 Act, the common law or otherwise, insofar as such loss, damage,
          expense, liability or claim arises out of or is based upon any untrue
          statement or alleged untrue statement of a material fact contained in
          the Registration Statement (or in the Registration Statement as
          amended by any post-effective amendment thereof by the Company) or in
          a Prospectus (the term "Prospectus" for the purpose of this Section 11
          being

                                      -22-
<PAGE>

          deemed to include any preliminary prospectus, the Prospectus and the
          Prospectus as it may be amended or supplemented by the Company), or
          arises out of or is based upon any omission or alleged omission to
          state a material fact required to be stated in either such
          Registration Statement or Prospectus or necessary to make the
          statements made therein not misleading, except insofar as any such
          loss, damage, expense, liability or claim arises out of or is based
          upon any untrue statement or alleged untrue statement of a material
          fact contained in and in conformity with information furnished in
          writing by the Agent to the Company expressly for use with reference
          to the Agent in such Registration Statement or such Prospectus or
          arises out of or is based upon any omission or alleged omission to
          state a material fact by the Agent in connection with such information
          required to be stated in such Registration Statement or such
          Prospectus or necessary to make such information not misleading.

          If any action, suit or proceeding (together, a "Proceeding") is
          brought against the Agent or any such person in respect of which
          indemnity may be sought against the Company pursuant to the foregoing
          paragraph, the Agent or such person shall promptly notify the Company
          in writing of the institution of such Proceeding and the Company shall
          assume the defense of such Proceeding, including the employment of
          counsel reasonably satisfactory to such indemnified party and payment
          of all reasonable fees and expenses; provided, however, that the
          omission to so notify the Company shall not relieve the Company from
          any liability which the Company may have to the Agent or any such
          person or otherwise. The Agent or such person shall have the right to
          employ its or their own counsel in any such case, but the fees and
          expenses of such counsel shall be at the expense of such Agent or of
          such person unless the employment of such counsel shall have been
          authorized in writing by the Company in connection with the defense of
          such Proceeding or the Company shall not have, within a reasonable
          period of time in light of the circumstances, employed counsel to have
          charge of the defense of such Proceeding or such indemnified party or
          parties shall have reasonably concluded based on advice of counsel
          that there may be defenses available to it or them which are different
          from, additional to or in conflict with those available to the
          Company, in which case the Company shall not have the right to direct
          the defense of such Proceeding on behalf of the indemnified party or
          parties, in any of which events such reasonable fees and expenses
          shall be borne by the Company and paid as incurred, it being
          understood, however, that the Company shall not be liable for the
          reasonable expenses of more than one separate counsel, in addition to
          any local counsel, in any one Proceeding or series of related
          Proceedings in the same jurisdiction representing the indemnified
          parties who are parties to such Proceeding. The Company shall not be
          liable for any settlement of any Proceeding effected without its
          written consent but if settled with the written consent of the
          Company, the Company agrees to indemnify and hold harmless the Agent
          and any such person from and against any loss or liability by reason
          of such settlement. 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 sentence of this paragraph, then the
          indemnifying party agrees that it shall be liable for any settlement

                                      -23-
<PAGE>


          of any Proceeding effected without its written consent if (i) such
          settlement is entered into more than 60 Exchange Business Days after
          receipt by such indemnifying party of the aforesaid request, (ii) such
          indemnifying party shall not have reimbursed the indemnified party in
          accordance with such request before the date of such settlement and
          (iii) such indemnified party shall have given the indemnifying party
          at least 30 days' prior notice of its intention to settle. 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 and does not include an
          admission of fault, culpability or a failure to act, by or on behalf
          of such indemnified party.

     (b)  The Agent agrees to indemnify, defend and hold harmless the Company,
          its directors and officers, and any person who controls the Company
          within the meaning of Section 15 of the Act or Section 20 of the 1934
          Act, and the successors and assigns of all of the foregoing persons
          from and against any loss, damage, expense, liability or claim
          (including the reasonable cost of investigation) which, jointly or
          severally, the Company or any such person may incur under the Act, the
          1934 Act, the common law or otherwise, insofar as such loss, damage,
          expense, liability or claim arises out of or is based upon any untrue
          statement or alleged untrue statement of a material fact contained in
          and in conformity with information furnished in writing by the Agent
          to the Company expressly for use with reference to the Agent in the
          Registration Statement, as amended by any post-effective amendment
          thereof by the Company, or in a Prospectus, or arises out of or is
          based upon any omission or alleged omission to state a material fact
          in connection with such information required to be stated in such
          Registration Statement or such Prospectus or necessary to make such
          information not misleading.

          If any Proceeding is brought against the Company or any such person in
          respect of which indemnity may be sought against the Agent pursuant to
          the foregoing paragraph, the Company or such person shall promptly
          notify the Agent in writing of the institution of such Proceeding and
          the Agent shall assume the defense of such Proceeding, including the
          employment of counsel reasonably satisfactory to such indemnified
          party and payment of all fees and expenses; provided, however, that
          the omission to so notify the Agent shall not relieve the Agent from
          any liability which the Agent may have to the Company or any such
          person or otherwise. The Company or such person shall have the right
          to employ its own counsel in any such case, but the fees and expenses
          of such counsel shall be at the expense of the Company or such person
          unless the employment of such counsel shall have been authorized in
          writing by the Agent in connection with the defense of such Proceeding
          or the Agent shall not have, within a reasonable period of time in
          light of the circumstances, employed counsel to have charge of the
          defense of such Proceeding or such indemnified party or parties shall
          have reasonably concluded that there may be defenses available to it
          or them which are different from or additional to or in conflict with
          those available to

                                      -24-
<PAGE>

          such Agent (in which case the Agent shall not have the right to direct
          the defense of such Proceeding on behalf of the indemnified party or
          parties, but the Agent may employ counsel and participate in the
          defense thereof but the fees and expenses of such counsel shall be at
          the expense of the Agent), in any of which events such reasonable fees
          and expenses shall be borne by the Agent and paid as incurred (it
          being understood, however, that the Agent shall not be liable for the
          reasonable expenses of more than one separate counsel (in addition to
          any local counsel) in any one Proceeding or series of related
          Proceedings in the same jurisdiction representing the indemnified
          parties who are parties to such Proceeding). The Agent shall not be
          liable for any settlement of any such Proceeding effected without the
          written consent of the Agent but if settled with the written consent
          of the Agent, the Agent agrees to indemnify and hold harmless the
          Company and any such person from and against any loss or liability by
          reason of such settlement. 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 sentence of this paragraph, then
          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 60 Exchange Business
          Days after receipt by such indemnifying party of the aforesaid
          request, (ii) such indemnifying party shall not have reimbursed the
          indemnified party in accordance with such request before the date of
          such settlement and (iii) such indemnified party shall have given the
          indemnifying party at least 30 days' prior notice of its intention to
          settle. 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.

     (c)  If the indemnification provided for in this Section 11 is unavailable
          to an indemnified party under subsections (a) and (b) of this Section
          11 in respect of any losses, damages, expenses, liabilities or claims
          referred to therein, then each applicable indemnifying party, in lieu
          of indemnifying such indemnified party, shall contribute to the amount
          paid or payable by such indemnified party as a result of such losses,
          damages, expenses, liabilities or claims (i) in such proportion as is
          appropriate to reflect the relative benefits received by the Company
          on the one hand and the Agent 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 Agent on the other in connection with the statements or
          omissions which resulted in such losses, damages, expenses,
          liabilities or claims, as well as any other relevant equitable
          considerations. The relative benefits received by the Company on the
          one hand and the Agent on the other shall be deemed to be in the same
          respective proportions as the total proceeds from the offering (net of
          underwriting discounts and commissions but before deducting expenses)

                                      -25-

<PAGE>

          received by the Company and the total underwriting discounts and
          commissions received by the Agent, bear to the aggregate public
          offering price of the Shares. The relative fault of the Company on the
          one hand and of the Agent on the other shall be determined by
          reference to, among other things, whether the untrue statement or
          alleged untrue statement of a material fact or omission or alleged
          omission relates to information supplied by the Company or by the
          Agent and the parties' relative intent, knowledge, access to
          information and opportunity to correct or prevent such statement or
          omission. The amount paid or payable by a party as a result of the
          losses, damages, expenses, liabilities and claims referred to in this
          subsection shall be deemed to include any legal or other fees or
          expenses reasonably incurred by such party in connection with
          investigating, preparing to defend or defending any Proceeding.

     (d)  The Company and the Agent agree that it would not be just and
          equitable if contribution pursuant to this Section 11 were determined
          by pro rata allocation or by any other method of allocation that does
          not take account of the equitable considerations referred to in
          subsection (c) above. Notwithstanding the provisions of this Section
          11, the Agent shall not be required to contribute any amount in excess
          of the amount by which the total price at which the Shares
          underwritten by such Agent and distributed to the public were offered
          to the public exceeds the amount of any damage which the Agent has
          otherwise been required to pay by reason of such untrue statement or
          alleged untrue statement or omission or alleged omission. No person
          guilty of fraudulent misrepresentation (within the meaning of Section
          11(f) of the Act) shall be entitled to contribution from any person
          who was not guilty of such fraudulent misrepresentation.

          The indemnity and contribution agreements contained in this Section 11
          and the covenants, warranties and representations of the Company
          contained in this Agreement shall remain in full force and effect
          regardless of any investigation made by or on behalf of the Agent, its
          directors or officers or any person (including each officer or
          director of such person) who controls the Agent within the meaning of
          Section 15 of the Act or Section 20 of the 1934 Act, or by or on
          behalf of the Company, its directors or officers or any person who
          controls the Company within the meaning of Section 15 of the Act or
          Section 20 of the 1934 Act, and shall survive any termination of this
          Agreement or the issuance and delivery of the Shares. The Company and
          the Agent agree promptly to notify each other of the commencement of
          any Proceeding against it and, against any of their respective
          officers or directors in connection with the issuance and sale of the
          Shares, or in connection with the Registration Statement or
          Prospectus.

     12. Notices. All notices hereunder shall be in writing and delivered by
hand, overnight courier, mail or facsimile, and if to the Agent, shall be
sufficient in all respects if delivered to UBS Warburg LLC, 677 Washington
Blvd., Stamford, CT 06901, with separate copies to the attention of:
________________ Facsimile No. (203) 719-____; Operations - Corporate Action
Department, Facsimile No. (203) 719-0795; and Legal Affairs (Equities Group),
Facsimile No. (203) 719-0680, and if to the Company, shall be sufficient in all
respects if delivered or sent to

                                      -26-
<PAGE>

the Company at the offices of the Company at 80 SW 8th Street, Miami, Florida
33130, Attention: Phil Gevas. Notwithstanding the foregoing, Purchase Notices
shall be delivered to the Agent by facsimile at (203) 719-____ and receipt
confirmed by telephone at (203) 719-____, and notices to the Company pursuant to
Section 1(d) shall be delivered to the Company by facsimile at ________________
and receipt confirmed by telephone at ______________. A Purchase Notice received
by the Agent after 4 p.m. on an Exchange Business Day or on a day that is not an
Exchange Business Day shall be deemed to have been delivered on the next
following Exchange Business Day.

     13. Governing Law; Construction. This Agreement and any claim, counterclaim
or dispute of any kind or nature whatsoever arising out of or in any way
relating to this Agreement ("Claim"), directly or indirectly, shall be governed
by, and construed in accordance with, the laws of the State of New York, other
than rules governing choice of applicable law. The Section headings in this
Agreement have been inserted as a matter of convenience of reference and are not
a part of this Agreement.

     14. Submission to Jurisdiction. Except as set forth below, no Claim may be
commenced, prosecuted or continued in any court other than the courts of the
State of New York located in the City and County of New York or in the United
States District Court for the Southern District of New York, which courts shall
have nonexclusive jurisdiction over the adjudication of such matters, and the
Company consents to the jurisdiction of such courts and personal service with
respect thereto. The Company hereby consents to personal jurisdiction, service
and venue in any court in which any Claim arising out of or in any way relating
to this Agreement is brought by any third party against UBS Warburg LLC or any
indemnified party. Each of UBS Warburg LLC and the Company, on its behalf and,
to the extent permitted by applicable law, on behalf of its stockholders and
affiliates, waives all right to trial by jury in any action, proceeding or
counterclaim, whether based upon contract, tort or otherwise, in any way arising
out of or relating to this Agreement. The Company agrees that a final judgment
in any such action, proceeding or counterclaim brought in any such court shall
be conclusive and binding upon the Company and may be enforced in any other
courts in the jurisdiction of which the Company is or may be subject, by suit
upon such judgment.

     15. Parties in Interest. The Agreement herein set forth has been and is
made solely for the benefit of the Agent and the Company and to the extent
provided in Section 11 hereof the controlling persons, directors and officers
referred to in such section, and their respective successors, assigns, heirs,
personal representatives and executors and administrators. No other person,
partnership, association or corporation (including a purchaser, as such
purchaser, from the Agent) shall acquire or have any right under or by virtue of
this Agreement.

     16. Counterparts. This Agreement may be signed by the parties in one or
more counterparts, which together shall constitute one and the same agreement
among the parties.

     17. Successors and Assigns. This Agreement shall be binding upon the Agent
and the Company and their successors and assigns and any successor or assign of
any substantial portion of the Company's and the Agent's respective businesses
and/or assets.

     18. Miscellaneous. UBS Warburg LLC, an indirect, wholly owned subsidiary of
UBS AG, is not a bank and is separate from any affiliated bank, including any
U.S. branch or agency of UBS AG. Because UBS Warburg LLC is a separately
incorporated entity, it is solely responsible for its own contractual
obligations and commitments, including obligations with respect to sales and
purchases of securities. Securities sold, offered or recommended by UBS Warburg
LLC are not deposits, are not insured by the Federal Deposit Insurance
Corporation, are not guaranteed by a branch or agency of UBS AG, and are not
otherwise an obligation or responsibility of a branch or agency of UBS AG.

     A lending affiliate of UBS Warburg LLC may have lending relationships with
issuers of securities underwritten or privately placed by UBS Warburg LLC. To
the extent required under the securities laws, prospectuses and other disclosure
documents for securities underwritten or privately placed by UBS Warburg LLC
will disclose the existence of any such lending relationships and whether the
proceeds of the issue will be used to repay debts owed to affiliates of UBS
Warburg LLC.

     UBS Warburg LLC and one or more of its affiliates may make markets in the
Common Stock or other securities of the Company, in connection with which they
may buy and sell, as agent or principal, for long or short account, shares of
Common Stock or other securities of the Company, at the same time that UBS
Warburg LLC is acting as Agent pursuant to this Agreement.

                                      -28-
<PAGE>


     If the foregoing correctly sets forth the understanding among the Company
and the Agent, please so indicate in the space provided below for the purpose,
whereupon this letter and your acceptance shall constitute a binding agreement
between the Company and the Agent.

                                   Very truly yours,


                                   APHTON CORPORATION



                                   By:_______________________
                                      Name:
                                      Title:


Accepted and agreed to as of the
date first above written:

UBS WARBURG LLC


By:__________________________
   Name:
   Title:


By:__________________________
   Name:
   Title:

                                      -29-
<PAGE>


                                                                      Schedule I

                           Subsidiaries of the Company

                   Currently, the Company has no subsidiaries.






                                      -30-

<PAGE>


                                                                       Exhibit A

                              Officers' Certificate

1.   The representations and warranties of the Company in the Distribution
     Agreement are true and correct in all material respects as of the date
     hereof as though made on and as of this date;

2.   The Company has performed all obligations and satisfied all conditions on
     its part to be performed or satisfied pursuant to the Distribution
     Agreement at or prior to the date hereof;

3.   The Company's Registration Statement (File No. 333-_____) under the
     Securities Act of 1933 has become effective; no stop order suspending the
     effectiveness of such Registration Statement has been issued and no
     proceeding for that purpose has been initiated or threatened by the
     Securities and Exchange Commission (the "Commission"); and all requests for
     additional information on the part of the Commission have been complied
     with; and

4.   Except as otherwise disclosed in writing to the Agent by the Company,
     subsequent to the respective dates as of which information is given in the
     Registration Statement and the Prospectus, there has not been (i) any
     material adverse change, or any development involving a prospective
     material adverse change, in the business, prospects, properties or assets
     described or referred to in the Registration Statement, or the results of
     operations, condition (financial or otherwise), business or operations of
     the Company and the Subsidiaries, whether or not arising in the ordinary
     course of business, or (ii) any transaction which is material to the
     Company or the Subsidiaries, planned or entered into by the Company or any
     of the Subsidiaries, or (iii) any obligation, direct or contingent, which
     is material to the Company and the Subsidiaries, incurred by the Company or
     the Subsidiaries, except obligations incurred in the ordinary course of
     business, or (iv) any material change in the capital stock or outstanding
     indebtedness of the Company or the Subsidiaries, or (v) any dividend or
     distribution of any kind declared, paid or made on the capital stock of the
     Company; and neither the Company nor the Subsidiaries has any material
     contingent obligation which is not disclosed in the Registration Statement.


                                      -31-

<PAGE>


                                                                       Exhibit B

                           Opinion of White & Case LLP

                      Aphton Corporation - Form of Opinion

i.     The Company has been duly incorporated and is validly existing as a
       corporation in corporate good standing under the laws of the State of
       Delaware and has the corporate power and authority to own, lease and
       operate its properties and conduct its business as described in the
       Registration Statement, and to enter into this Agreement, to issue, sell
       and deliver the Shares and consummate the transactions contemplated in
       the Prospectus;

ii.    The common stock of the Company, including the Shares, conforms in all
       material respects to the description thereof contained in the
       Registration Statement and Prospectus;

iii.   The Shares have been duly and validly authorized by the Company for
       offer, sale, issuance and delivery pursuant to this Agreement and, when
       issued and delivered against payment therefor as provided in the
       Distribution Agreement, will be duly and validly issued and fully paid
       and non-assessable;

iv.    To such counsel's knowledge, the Company is duly qualified to do business
       as a foreign corporation and in good standing in each jurisdiction where
       the ownership or leasing of its properties or the conduct of its business
       requires such qualification, except where the failure to so qualify would
       not have a material adverse effect on the business, properties, financial
       condition or results of operation of the Company taken as a whole (a
       "Material Adverse Effect");

v.     To such counsel's knowledge and other than as set forth in the
       Prospectus, there are no actions, suits, claims, investigations or
       proceedings pending or threatened to which the Company is a party or of
       which any of their respective properties is subject at law or in equity,
       or before or by any federal, state or local governmental or regulatory
       commission, board, body, authority or agency, which could prevent
       consummation of the transactions contemplated hereby or which are
       required to be described in the Registration Statement or the Prospectus
       but are not so described;

vi.    This Agreement has been duly authorized, executed and delivered by the
       Company;

vii.   The execution, delivery and performance of this Agreement, the issuance
       and sale of the Shares and the consummation of the transactions
       contemplated hereby will not conflict with, or result in any breach of or
       constitute a default under (nor constitute any event which with notice,
       lapse of time, or both would result in any breach of, or constitute a
       default under), any provisions of the charter or by-laws of the Company
       or, to such counsel's knowledge, under any provision of any license,
       indenture, mortgage, deed of trust, bank loan or credit agreement or
       other evidence of indebtedness, or any lease, contract or other agreement
       or instrument to which the Company is a party or by which any of them or
       their respective properties may be bound or affected and which have been
       filed by the Company with the Commission under the Securities Exchange
       Act of 1934, as amended (the "Exchange Act"), and are listed in the
       exhibit index to the Company's most recent Annual Report on Form 10-K or
       are subsequently filed under the Exchange Act, or under any decree,
       judgment or order


                                      -32-

<PAGE>


       known to such counsel to be applicable to the Company or under any
       federal, state or local law, regulation or rule;

viii.  No approval, authorization, consent or order of or filing with any
       national, state or local governmental or regulatory commission, board,
       body, authority or agency is required in connection with the issuance and
       sale of the Shares or the consummation by the Company of the transactions
       as contemplated hereby except such as may be required by the Act and the
       applicable rules and regulations thereunder, the securities or blue sky
       laws of the various jurisdictions in which the Shares are being offered
       by the Agent (as to which such counsel expresses no opinion) or under the
       rules and regulations of the National Association of Securities Dealers,
       Inc. ("NASD") (as to which such counsel expresses no opinion);

ix.    The statements set forth in the Prospectus in the second sentence of the
       fourth paragraph under the caption "The Company", under the caption "Risk
       Factors--Our potential products are in the early stages of product
       development", "Risk Factors--We expect to continue incurring operating
       losses in the next several years", "Risk Factors--We have substantial
       capital requirements and we may not be able to obtain additional
       financing", "Risk Factors--Our different approach to disease treatment
       may not prove successful", "Risk Factors--The development of our products
       is subject to extensive regulation", "Risk Factors--We depend on
       strategic alliances and may need additional strategic collaborators in
       the future", "Risk Factors--The industry in which we operate is
       characterized by rapid technological change and intense competition",
       "Risk Factors--Our ability to enforce our patents and proprietary rights
       is uncertain", "Risk Factors--We depend on key personnel", "Risk
       Factors--We may be exposed to product liability claims and uninsured
       risk", "Risk Factors--Our business involves the use of hazardous
       materials that could expose us to environmental liability", "Risk
       Factors--We depend on others for manufacturing and marketing", "Risk
       Factors--Future healthcare reforms may adversely affect our financial
       results", "Risk Factors--Our success depends on third party
       reimbursement", "Risk Factors--Ownership of our common stock is
       concentrated", "Risk Factors--The price of our common stock may be
       volatile" , "Risk Factors--The exercise of outstanding warrants and other
       rights to obtain additional shares could dilute the value of the shares"
       and Item 15 of the Registration statement, insofar as they purport to
       describe the provisions of the laws and documents referred to therein,
       fairly summarize the matters referred to therein in all material
       respects;

x.     The Company is not and, after giving effect to the offering and sale of
       the Shares, will not be required to register as an "investment company"
       as such term is defined in the Investment Company Act of 1940, as amended
       (the "Investment Company Act");

xi.    The documents incorporated by reference in the Prospectus or any further
       amendment or supplement thereto made by the Company prior to the date of
       delivery of such opinion (other than the financial statements and related
       schedules therein, as to which such counsel need express no opinion),
       when they became effective or were filed with the Commission, as the case
       may be, complied as to form in all material respects with the
       requirements of the Act or the Exchange Act, as applicable, and the rules
       and regulations of the Commission thereunder;

                                      -33-
<PAGE>

xii.   The Registration Statement and the Prospectus and any further amendments
       and supplements thereto made by the Company prior to the date of delivery
       of such opinion (other than the financial statements and related
       schedules therein, as to which such counsel need express no opinion)
       comply as to form in all material respects with the requirements of the
       Act and the rules and regulations of the Commission thereunder.

       Such counsel shall also state that, although they do not assume any
responsibility for the accuracy, completeness or fairness of the statements
contained in the Registration Statement or the Prospectus, except for those
referred to in the opinion in paragraphs (ii) and (ix) above, nothing has come
to their attention that has led them to believe (a) that, as of its effective
date, the Registration Statement or, as of its date, any further amendment
thereto made by the Company prior to the date of delivery of such opinion (other
than the financial statements and related schedules therein, as to which such
counsel need express no belief) contained an untrue statement of a material fact
or omitted to state a material fact required to be stated therein or necessary
to make the statements therein not misleading or (b) that, as of its date, the
Prospectus and documents incorporated by reference therein or any further
amendment or supplement to the Prospectus (and documents incorporated by
reference therein) made by the Company prior to the time and date of delivery of
such opinion (other than the financial statements and related schedules therein,
as to which such counsel need express no belief) contained an untrue statement
of a material fact or omitted to state a material fact necessary to make the
statements therein, in the light of the circumstances under which they were
made, not misleading or (c) that, as of the date of delivery of such opinion,
either the Registration Statement or the Prospectus or any further amendment or
supplement thereto made by the Company prior to the time and date of delivery of
such opinion (other than the financial statements and related schedules therein,
as to which such counsel need express no belief) contains an untrue statement of
a material fact or omits to state a material fact necessary to make the
statements therein, in the light of the circumstances under which they were
made, not misleading; and they do not know of any amendment to the Registration
Statement required to be filed or of any contracts or other documents of a
character required to be filed as an exhibit to the Registration Statement or
required to be incorporated by reference into the Prospectus or required to be
described in the Registration Statement or the Prospectus which are not filed or
incorporated by reference or described as required.

                                      -34-

<PAGE>


                                                                       Exhibit C

                Intellectual Property Opinion of White & Case LLP


                     [Form of Intellectual Property Opinion]

[ADDRESS]

[OPINION LETTER TO UNDERWRITERS]


RE:      Aphton Corporation
         Pursuant to Distribution Agreement


Ladies and Gentlemen:

         We are Intellectual Property Counsel for the Company in connection with
certain intellectual property matters and in connection with the distribution of
shares of Aphton Corporation (the "Company") common stock ("Common Stock")
pursuant to the Distribution Agreement as agreed to on _________________. This
opinion is provided pursuant to the above referenced Distribution Agreement
between the Company and the Underwriters.

         In connection with this opinion, we have been asked to review
statements relating to patents, patent applications and trade secrets (the
"Intellectual Property") of the Company and as made in or referenced by the
Distribution Agreement. We have made this review and provide our opinion with
respect to the above-identified sections of these documents. Our opinion is
limited to Intellectual Property matters, as noted above.

         We are familiar with certain of the technology used by the Company in
its business, to the extent of its disclosure to us by the Company, which is the
subject matter of certain of the patents, patent applications and trade secrets
described in the above identified documents. The opinions and beliefs expressed
in this letter represent our considered judgment and are based upon compilations
of applicable laws generally available to the public and effective as of the
date hereof.

                                      -35-

<PAGE>


         As used in this letter, the phrase "to our knowledge" when used as a
qualification with respect to the existence or absence of any matter, means
that, during our representation of the Company and having no independent
investigation with respect thereto, no information has come to our attention
which has given us actual knowledge of the existence of facts contrary to the
stated existence or absence of the matter.

         Based on our review of the above-identified sections of the
Distribution Agreement, and subject to and limited by the foregoing and the
exceptions and limitations set forth below, we offer the following opinions and
conclusions:


     1.   For the purpose of this opinion, the terms "know," "known," or
          "knowledge" refer to the actual knowledge by us, as well as the
          knowledge arising from our review of documents and materials relevant
          to the matters addressed in the paragraphs below, and the knowledge
          arising from our inquiry of employees or officers of the Company
          familiar with a matter to which this opinion pertains.

     2.   All patents and pending patent applications ("Patents") that are owned
          by or licensed to the Company are listed on IP Schedule A, attached
          hereto. Information concerning the application number, filing data,
          and status of the applications encompassed by our representation of
          the Company is set forth in IP Schedule A.

     3.   Except as set forth below, to our knowledge, the statements in the
          Distribution Agreement, insofar as such statements pertain to
          Intellectual Property matters, accurately and fairly represent the
          information referred to therein. We express no opinion, however, as to
          the bases upon which the Company decides to file patent applications,
          the dependency of the Company's commercial success on any factors
          including protection of proprietary technology and the procurement and
          enforceability of patents, nor as to the Company's reliance on various
          methods to protect its proprietary rights.

     4.   To our knowledge, and based upon a representation by the Company
          regarding the conception and reduction to practice of the patents,
          patent applications and trade secrets related to the technology
          described in the above-identified documents, (A) there are no rights
          of parties other than the Company to any of the patents, patent
          applications or trade secret rights related to the technology
          described in the Distribution Agreement, (B) there are no pending or
          threatened actions, suits, proceedings or claims by others challenging
          the Company's rights to or in any such patents, patent applications or
          trade secret rights and (C) there are no pending or threatened
          actions, suits, proceedings or claims by others that the Company is
          infringing or otherwise violating any patent or trade secret rights of
          others.
                                      -36-
<PAGE>

     5.   To the best of our knowledge, the Company and its licensors have
          complied with the examination requirements of the United States Patent
          and Trademark Office ("USPTO") duty of candor and disclosure for each
          of the United States Patent listed in IP Schedule A. No fact has come
          to such counsel's attention that causes such counsel to question the
          enforceability of any of the Patents, or to question the validity of
          any claim of an issued patent or pending patent application listed on
          IP Schedule A.

     6.   We are aware of no legal or governmental proceedings relating to the
          Company's patent rights, other than normal ex parte USPTO examination
          proceedings. No patent application listed in IP Schedule A has been
          formally abandoned, and all patents have been lawfully issued.

     7.   To our knowledge, there are no facts or circumstances which, if
          asserted in litigation, would be likely to render any of the trade
          secret rights reflected in the Company's filed patent applications
          invalid, or unenforceable except to the extent they have been or will
          be disclosed upon publication of such patent applications or upon the
          issuance of patents.

     8.   There are no agreements with third parties relating to the
          acquisition, licensing and/or transfer of intellectual property rights
          which have or are anticipated to have a material impact on the
          Company's existing or future business, including license agreements,
          joint venture agreements, marketing and/or distribution agreements or
          other collaboration agreements, that are not currently in effect or
          that will be expiring soon, nor further has there been any notice of
          termination or other act indicating a desire to terminate any of the
          aforesaid agreements.

     9.   Except as described in the above identified documents, we are not
          aware of any facts that prevent the Company from using its
          intellectual property and know-how conduct its business or from
          enforcing its rights to its patents or patent applications.

     10.   We are not aware of any facts or prior art that would lead us to
          believe that any of the Companies patents are or may infringe the
          patent or patents of third parties.


     11.  We believe and have so informed the Company that its _________
          products are covered by one or more of the issued patents and the
          claims therein listed in IP Schedule A, attached hereto.

         This letter is limited to the matters set forth herein, and no matter
may be inferred or implied beyond the matters expressly stated in this letter.
We assume no obligation to advise you, subsequent to the delivery of this
letter, of any matters that could result in a change in the opinions or beliefs
set forth herein. This letter has been prepared solely for your use in
connection with the Purchase and/or Distribution of stock shares under the
appropriate

                                      -37-
<PAGE>

documents, and may not be used for any other purpose, or be relied upon by any
other person or entity. It should not be quoted in whole or in part or otherwise
be referred to, nor be filed with nor furnished to any governmental agency or
other person or entity, without the prior written consent of the undersigned.


                                            Very Truly Yours,



                                            [Law Firm]

                                      -38-
<PAGE>



                                                                       Exhibit D

                       Comfort Letter of Ernst & Young LLP

1.   We are independent public accountants with respect to the Company [and its
     Subsidiaries] within the meaning of the Securities Act of 1933 and the
     Regulations promulgated thereunder (collectively, the "Act").

2.   In our opinion, the [consolidated] financial statements of the Company [and
     its Subsidiaries] audited by us and included or incorporated by reference
     in the Registration Statement and Prospectus comply as to form in all
     material respects with the applicable accounting requirements of the Act
     with respect to registration statements on Form S-3 and the Securities
     Exchange Act of 1934 and the Regulations promulgated thereunder
     (collectively, the "1934 Act").

3.   On the basis of procedures (but not an audit in accordance with generally
     accepted auditing standards) consisting of:

     (a)  Reading the minutes of the meetings of the stockholders, the Board of
          Directors, Executive Committee and Audit Committee of the Company [and
          the Boards of Directors and Executive Committees of its Subsidiaries]
          as set forth in the minute books through [less than five business days
          prior to the Closing Date];

     (b)  Performing the procedures specified by the American Institute of
          Certified Public Accountants for a review of interim financial
          information as described in FAS No. 71, Interim Financial Information,
          on the unaudited condensed [consolidated] interim financial statements
          of the Company [and its consolidated Subsidiaries] included or
          incorporated by reference in the Registration Statement and Prospectus
          and reading the unaudited interim financial data, if any, for the
          period from the date of the latest balance sheet included or
          incorporated by reference in the Registration Statement and Prospectus
          to the date of the latest available interim financial data; and

     (c)  Making inquiries of certain officials of the Company who have
          responsibility for financial and accounting matters regarding the
          specific items for which representations are requested below, nothing
          has come to our attention as a result of the foregoing procedures that
          causes us to believe that:

          (i)  the unaudited condensed [consolidated] interim financial
               statements, included or incorporated by reference in the
               Registration Statement and Prospectus, do not comply as to form
               in all material respects with the applicable accounting
               requirements of the 1934 Act and the published rules and
               regulations thereunder;

          (ii) any material modifications should be made to the unaudited
               condensed [consolidated] interim financial statements, included
               or incorporated by reference in the Registration Statement and
               Prospectus, for them to be in conformity with generally accepted
               accounting principles;


                                      -39-
<PAGE>

          (iii) (x) at the date of the latest available interim financial data
               and [less than five business days prior to the Closing Date],
               there was any change in the capital stock or the long-term debt
               (other than scheduled repayments of such debt) or any decreases
               in stockholders' equity of the Company [and the Subsidiaries on a
               consolidated basis] as compared with the amounts shown in the
               latest balance sheet included or incorporated by reference in the
               Registration Statement and the Prospectus or (y) for the period
               from the date of the latest available financial data to less than
               three business days prior to the Closing Date, there was any
               change in the capital stock or the long-term debt (other than
               scheduled repayments of such debt) or any decreases in
               stockholders' equity of the Company [and the Subsidiaries on a
               consolidated basis], except in all instances for changes or
               decreases which the Registration Statement and Prospectus
               discloses have occurred or may occur [, apart from the following
               changes or decreases:].

4.   We have carried out certain other specified procedures, not constituting an
     audit, with respect to certain amounts, percentages and financial
     information which are included or incorporated by reference in the
     Registration Statement and Prospectus and which have been specified by the
     Agent and agreed to by us in a side letter, and we have found such amounts,
     percentages and financial information to be in agreement with the relevant
     accounting, financial and other records of the Company [and its
     Subsidiaries] identified in such letter.

                                      -40-

<PAGE>


                                                                       Exhibit E

                    Opinion of Stroock & Stroock & Lavan LLP

1.   The Company is a corporation duly organized, validly existing and in good
     standing under the laws of the State of Delaware. The Company is qualified
     to do business as a foreign corporation in good standing in the State of
     Florida. [Each Subsidiary of the Company has been duly organized or formed
     and is validly existing as a corporation, limited partnership, limited
     liability company or partnership, as the case may be, in good standing
     under the laws of its jurisdiction of organization or formation. Each
     Subsidiary of the Company is qualified to do business as a foreign
     corporation, limited partnership, limited liability company or partnership,
     as the case may be, in good standing in Delaware.]

2.   All of the outstanding shares of capital stock of the Company have been
     duly authorized and validly issued and are fully paid and nonassessable and
     were not issued in violation of or subject to any preemptive or similar
     rights. [All of the issued and outstanding shares of capital stock of each
     Subsidiary of the Company have been duly authorized and validly issued, and
     are fully paid and nonassessable and were not issued in violation of or
     subject to any preemptive or similar rights. The issued shares of capital
     stock of each of the Company's Subsidiaries are owned of record, directly
     or indirectly, by the Company free and clear of any and all liens, charges,
     claims, security interests or encumbrances.]

3.   The Company has full corporate power and authority to enter into the
     Distribution Agreement and to issue, sell and deliver the Shares to the
     Agent as agent or to the Agent as principal, as provided in the
     Distribution Agreement, and the Distribution Agreement has been duly
     authorized, executed and delivered by the Company and is the legal, valid
     and binding obligation of the Company, enforceable against the Company in
     accordance with its terms.

While we have not verified, and are not passing upon and do not assume any
responsibility for, the accuracy, completeness or fairness of the statements
contained in the Registration Statement and the Prospectus, we have participated
in conferences with certain officers and other representatives of the Company,
counsel for the Company, representatives of the independent auditors for the
Company and your representatives, at which the contents of the Registration
Statement and Prospectus and related matters were discussed and, on the basis of
the foregoing (relying as to materiality to a large extent on the opinions of
officers and other representatives of the Company), no facts have come to our
attention that lead us to believe that the Registration Statement (except with
respect to the financial statements, schedules and other financial data,
including therein, as to which we make no statement), at the time it became
effective, contained any untrue statement of a material fact or omitted to state
any material fact required to be stated therein or necessary in order to make
the statements therein, in the light of the circumstances under which they were
made, not misleading or that the Prospectus (except with respect to the
financial statements, schedules and other financial data included therein, as to
which we make no statement), as of its date, and as of the date hereof, contains
any untrue statement of a material

                                      -41-

<PAGE>

fact or omits 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.

                                      -42-