EXHIBIT 1.1


                                2,500,000 SHARES



                                 MEGABIOS CORP.



                                  COMMON STOCK



                             UNDERWRITING AGREEMENT

                           DATED SEPTEMBER ___, 1997

 
                               TABLE OF CONTENTS

 
                                                                                                      
SECTION 1.  REPRESENTATIONS AND WARRANTIES OF THE COMPANY..........................................        2
     Compliance with Registration Requirements.....................................................        2
     Offering Materials Furnished to Underwriters..................................................        2
     Distribution of Offering Material By the Company..............................................        3
     The Underwriting Agreement....................................................................        3
     Authorization of the Common Shares............................................................        3
     No Applicable Registration or Other Similar Rights............................................        3
     No Material Adverse Change....................................................................        3
     Independent Accountants.......................................................................        3
     Preparation of the Financial Statements.......................................................        4
     Incorporation and Good Standing of the Company................................................        4
     Capitalization and Other Capital Stock Matters................................................        4
     Stock Exchange Listing........................................................................        5
     Non-Contravention of Existing Instruments; No Further Authorizations or Approvals Required....        5
     No Material Actions or Proceedings............................................................        5
     Intellectual Property Rights..................................................................        6
     All Necessary Permits, etc....................................................................        6
     Title to Properties...........................................................................        6
     Tax Law Compliance............................................................................        6
     Company Not an Investment Company..................................ERROR! Bookmark not defined
     Insurance.....................................................................................        7
     No Price Stabilization or Manipulation........................................................        7
     Related Party Transactions....................................................................        7
     Reincorporation...............................................................................        7
     No Unlawful Contributions or Other Payments...................................................        8
     Company's Accounting System...................................................................        8
     Compliance with Environmental Laws............................................................        8
     Periodic Review of Costs of Environmental Compliance..........................................        9
     ERISA Compliance..............................................................................        9
SECTION 2.  PURCHASE, SALE AND DELIVERY OF COMMON SHARES...........................................        9
     The Firm Common Shares........................................................................        9
     The First Closing Date........................................................................       10
     The Optional Common Shares; the Second Closing Date...........................................       10
     Public Offering of the Common Shares..........................................................       11
     Payment for the Common Shares.................................................................       11
     Delivery of the Common Shares.................................................................       11
     Delivery of Prospectus to the Underwriters....................................................       11
SECTION 3.  ADDITIONAL COVENANTS OF THE COMPANY....................................................       11
     Representatives' Review of Proposed Amendments and Supplements................................       11
 
                                       i

 
 
                                                                                                        
     Securities Act Compliance.....................................................................       12
     Amendments and Supplements to the Prospectus and Other Securities
       Act Matters.................................................................................       12
     Copies of any Amendments and Supplements to the Prospectus....................................       12
     Blue Sky Compliance...........................................................................       12
     Use of Proceeds...............................................................................       13
     Transfer Agent................................................................................       13
     Earnings Statement............................................................................       13
     Periodic Reporting Obligations................................................................       13
     Agreement Not To Offer or Sell Additional Securities..........................................       13
     Agreement Not To Release Lock-Ups.............................................................       14
     Future Reports to the Representatives.........................................................       14
SECTION 4.  PAYMENT OF EXPENSES....................................................................       14
SECTION 5.  CONDITIONS OF THE OBLIGATIONS OF THE UNDERWRITERS......................................       15
     Accountants' Comfort Letter...................................................................       15
     Compliance with Registration Requirements; No Stop Order; No Objection
       from NASD...................................................................................       15
     No Material Adverse Change or Ratings Agency Change...........................................       15
     Opinion of Counsel for the Company............................................................       16
     Opinion of Intellectual Property Counsel for the Company......................................       16
     Opinion of Counsel for the Underwriters.......................................................       16
     Officers' Certificate.........................................................................       16
     Bring-down Comfort Letter.....................................................................       16
     Lock-Up Agreement from Certain Stockholders of the Company....................................       17
     Additional Documents..........................................................................       17
SECTION 6.  REIMBURSEMENT OF UNDERWRITERS' EXPENSES................................................       17
SECTION 7.  EFFECTIVENESS OF THIS AGREEMENT........................................................       17
SECTION 8.  INDEMNIFICATION........................................................................       18
     Indemnification of the Underwriters...........................................................       18
     Indemnification of the Company, its Directors and Officers....................................       19
     Notifications and Other Indemnification Procedures............................................       19
     Settlements...................................................................................       20
SECTION 9.  CONTRIBUTION...........................................................................       21
SECTION 10.  DEFAULT OF ONE OR MORE OF THE SEVERAL UNDERWRITERS....................................       22
SECTION 11.  TERMINATION OF THIS AGREEMENT.........................................................       22
SECTION 12.  REPRESENTATIONS AND INDEMNITIES TO SURVIVE DELIVERY...................................       23
SECTION 13.  NOTICES...............................................................................       23
 

                                      ii

 
 
                                                                                                       
SECTION 14.  SUCCESSORS............................................................................       24
SECTION 15.  PARTIAL UNENFORCEABILITY..............................................................       24
SECTION 16.  GOVERNING LAW PROVISIONS..............................................................       24
SECTION 17.  GENERAL PROVISIONS....................................................................       25


                                      iii

 
                             UNDERWRITING AGREEMENT



                                                              September __, 1997


MONTGOMERY SECURITIES
HAMBRECHT & QUIST LLC
As Representatives of the several Underwriters
c/o MONTGOMERY SECURITIES
600 Montgomery Street
San Francisco, California  94111


Ladies and Gentlemen:

          INTRODUCTORY.  Megabios Corp., a Delaware corporation (the "Company"),
proposes to issue and sell to the several underwriters named in Schedule A (the
                                                                ----------     
"Underwriters") an aggregate of 2,500,000 shares (the "Firm Common Shares") of
its Common Stock, par value $0.001 per share (the "Common Stock").  In addition,
the Company has granted to the Underwriters an option to purchase up to an
additional 375,000 shares (the "Optional Common Shares") of Common Stock, as
provided in Section 2.  The Firm Common Shares and, if and to the extent such
option is exercised, the Optional Common Shares are collectively called the
"Common Shares."  Montgomery Securities and Hambrecht & Quist LLC have agreed to
act as representatives of the several Underwriters (in such capacity, the
"Representatives") in connection with the offering and sale of the Common
Shares.  The Company is successor by merger to Megabios Corp., a California
corporation (the "Predecessor"), as a result of a reincorporation transaction
that became effective on September [__,] 1997 (the "Reincorporation").

          The Company has prepared and filed with the Securities and Exchange
Commission (the "Commission") a registration statement on Form S-1 (File
No. 333-[___]), which contains a form of prospectus to be used in connection
with the public offering and sale of the Common Shares.  Such registration
statement, as amended, including the financial statements, exhibits and
schedules thereto, in the form in which it was declared effective by the
Commission under the Securities Act of 1933 and the rules and regulations
promulgated thereunder (collectively, the "Securities Act"), including any
information deemed to be a part thereof at the time of effectiveness pursuant to
Rule 430A or Rule 434 under the Securities Act, is called the "Registration
Statement."  Any registration statement filed by the Company pursuant to
Rule 462(b) under the Securities Act is called the "Rule 462(b) Registration
Statement," and from and after the date and time of filing of the Rule 462(b)
Registration Statement the term "Registration Statement" shall include the
Rule 462(b) Registration Statement.  Such prospectus, in the form first used by
the Underwriters to confirm sales of the Common Shares, is called the
"Prospectus"; provided, however, if the Company has, with the consent of
Montgomery Securities, elected to rely upon Rule 434 under the Securities Act,
the term "Prospectus" shall mean the Company's prospectus subject to completion
(each, 

                                       A
                                       

 
a "preliminary prospectus") dated August [__], 1997 (such preliminary prospectus
is called the "Rule 434 preliminary prospectus"), together with the applicable
term sheet (the "Term Sheet") prepared and filed by the Company with the
Commission under Rules 434 and 424(b) under the Securities Act and all
references in this Agreement to the date of the Prospectus shall mean the date
of the Term Sheet. All references in this Agreement to the Registration
Statement, the Rule 462(b) Registration Statement, a preliminary prospectus, the
Prospectus or the Term Sheet, or any amendments or supplements to any of the
foregoing, shall include any copy thereof filed with the Commission pursuant to
its Electronic Data Gathering, Analysis and Retrieval System ("EDGAR").

          The Company hereby confirms its agreements with the Underwriters as
follows:

     SECTION 1.  REPRESENTATIONS AND WARRANTIES OF THE COMPANY.

     The Company hereby represents, warrants and covenants to each Underwriter
as follows:
 
     (a) Compliance with Registration Requirements. The Registration Statement
  and any Rule 462(b) Registration Statement have been declared effective by the
  Commission under the Securities Act. The Company has complied to the
  Commission's satisfaction with all requests of the Commission for additional
  or supplemental information. No stop order suspending the effectiveness of the
  Registration Statement or any Rule 462(b) Registration Statement is in effect
  and no proceedings for such purpose have been instituted or are pending or, to
  the best knowledge of the Company, are contemplated or threatened by the
  Commission.

     Each preliminary prospectus and the Prospectus when filed complied in all
  material respects with the Securities Act and, if filed by electronic
  transmission pursuant to EDGAR (except as may be permitted by Regulation S-T
  under the Securities Act), was identical to the copy thereof delivered to the
  Underwriters for use in connection with the offer and sale of the Common
  Shares.  Each of the Registration Statement, any Rule 462(b) Registration
  Statement and any post-effective amendment thereto, at the time it became
  effective and at all subsequent times, complied and will comply in all
  material respects with the Securities Act and did not and will not contain any
  untrue statement of a material fact or omit to state a material fact required
  to be stated therein or necessary to make the statements therein not
  misleading.  The Prospectus, as amended or supplemented, as of its date and at
  all subsequent times, did not and will not contain any 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.  The representations and warranties set forth in the two
  immediately preceding sentences do not apply to statements in or omissions
  from the Registration Statement, any Rule 462(b) Registration Statement, or
  any post-effective amendment thereto, or the Prospectus, or any amendments or
  supplements thereto, made in reliance upon and in conformity with information
  relating to any Underwriter furnished to the Company in writing by the
  Representatives expressly for use therein.  There are no contracts or other
  documents required to be described in the Prospectus or to be filed as
  exhibits to the Registration Statement which have not been described or filed
  as required.

     (b) Offering Materials Furnished to Underwriters. The Company has delivered
  to the Representatives three complete manually signed copies of the
  Registration Statement and 

                                       2

 
  of each consent and certificate of experts filed as a part thereof, and
  conformed copies of the Registration Statement (without exhibits) and
  preliminary prospectuses and the Prospectus, as amended or supplemented, in
  such quantities and at such places as the Representatives have reasonably
  requested for each of the Underwriters.

        (c) Distribution of Offering Material By the Company.  Neither the
  Company nor the Predecessor have distributed, nor will the Company distribute,
  prior to the later of the Second Closing Date (as defined below) and the
  completion of the Underwriters' distribution of the Common Shares, any
  offering material in connection with the offering and sale of the Common
  Shares other than a preliminary prospectus, the Prospectus or the Registration
  Statement.

        (d) The Underwriting Agreement.  This Agreement has been duly
  authorized, executed and delivered by, and is a valid and binding agreement
  of, the Company, enforceable in accordance with its terms, except as rights to
  indemnification hereunder may be limited by applicable law and except as the
  enforcement hereof may be limited by bankruptcy, insolvency, reorganization,
  moratorium or other similar laws relating to or affecting the rights and
  remedies of creditors or by general equitable principles.

        (e) Authorization of the Common Shares.  The Common Shares to be
  purchased by the Underwriters from the Company have been duly authorized for
  issuance and sale pursuant to this Agreement and, when issued and delivered by
  the Company pursuant to this Agreement, will be validly issued, fully paid and
  nonassessable.

        (f) No Applicable Registration or Other Similar Rights.  There are no
  persons with registration or other similar rights to have any equity or debt
  securities registered for sale under the Registration Statement or included in
  the offering contemplated by this Agreement, except for such rights as have
  been duly waived or have expired by reason of lapse of time.

        (g) No Material Adverse Change.  Except as otherwise disclosed in the
  Prospectus, subsequent to the respective dates as of which information is
  given in the Prospectus: (i) there has been no material adverse change, or any
  development that could reasonably be expected to result in a material adverse
  change, in the condition, financial or otherwise, or in the earnings,
  business, operations or prospects, whether or not arising from transactions in
  the ordinary course of business, of the Company (any such change is called a
  "Material Adverse Change"); (ii) neither the Company nor the Predecessor has
  incurred any material liability or obligation, indirect, direct or contingent,
  not in the ordinary course of business nor entered into any material
  transaction or agreement not in the ordinary course of business; and
  (iii) there has been no dividend or distribution of any kind declared, paid or
  made by the Company on any class of capital stock or repurchase or redemption
  by the Company of any class of capital stock.

        (h) Independent Accountants.  Ernst & Young LLP, who have expressed
  their opinion with respect to the financial statements (which term as used in
  this Agreement includes the related notes thereto) filed with the Commission
  as a part of the Registration Statement and included in the Prospectus, are
  independent public or certified public accountants as required by the
  Securities Act.

                                      3 

 
        (i) Preparation of the Financial Statements.  The financial statements
  filed with the Commission as a part of the Registration Statement and included
  in the Prospectus present fairly the financial position of the Company as of
  and at the dates indicated and the results of their operations and cash flows
  for the periods specified.  Such financial statements have been prepared in
  conformity with generally accepted accounting principles applied on a
  consistent basis throughout the periods involved, except as may be expressly
  stated in the related notes thereto.  No other financial statements or
  supporting schedules are required to be included in the Registration
  Statement.  The financial data set forth in the Prospectus under the captions
  "Prospectus Summary--Summary Financial Data," "Selected Financial Data" and
  "Capitalization" fairly present the information set forth therein on a basis
  consistent with that of the audited financial statements contained in the
  Registration Statement.

        (j) Incorporation and Good Standing of the Company. The Company has been
  duly incorporated and is validly existing as a corporation in good standing
  under the laws of the jurisdiction of its incorporation and has corporate
  power and authority to own, lease and operate its properties and to conduct
  its business as described in the Prospectus and to enter into and perform its
  obligations under this Agreement.  The Company is duly qualified as a foreign
  corporation to transact business and is in good standing in the State of
  California and each other jurisdiction in which such qualification is
  required, whether by reason of the ownership or leasing of property or the
  conduct of business, except for such jurisdictions (other than the State of
  California) where the failure to so qualify or to be in good standing would
  not, individually or in the aggregate, result in a Material Adverse Change.
  Immediately prior to the Reincorporation, the Predecessor was duly
  incorporated and was validly existing as a corporation in good standing under
  the laws of the State of California and was duly qualified as a foreign
  corporation to transact business and was in good standing in each jurisdiction
  in which such qualification was required, whether by reason of the ownership
  or leasing of property or the conduct of business, except for such
  jurisdictions where the failure to so qualify or to be in good standing would
  not have resulted, individually or in the aggregate, in a material adverse
  change in the condition, financial or otherwise, or in the earnings, business,
  operations or prospects, whether or not arising from transactions in the
  ordinary course of business, of the Predecessor.  The Company does not own or
  control, directly or indirectly, any corporation, association or other entity
  and immediately prior to the Reincorporation the Predecessor had no
  subsidiaries other than the Company.

        (k) Capitalization and Other Capital Stock Matters.  The authorized,
  issued and outstanding capital stock of the Company is as set forth in the
  Prospectus under the caption "Capitalization" (other than for subsequent
  issuances, if any, pursuant to employee benefit plans described in the
  Prospectus, upon exercise of outstanding options or warrants described in the
  Prospectus or upon exercise of options granted after June 30, 1997, consistent
  with past practices, pursuant to employee benefit plans described in the
  Prospectus).  The Common Stock (including the Common Shares) conforms in all
  material respects to the description thereof contained in the Prospectus.
  Immediately prior to the Reincorporation, all of the issued and outstanding
  shares of capital stock of the Predecessor had been duly authorized and
  validly issued, were fully paid and nonassessable, had been issued in
  compliance with federal and state securities laws and none of such shares were
  issued in violation of any preemptive rights, rights of first refusal or other
  rights to subscribe for or purchase equity securities of the Predecessor. All
  of the issued and outstanding shares of

                                       4

 
  Common Stock have been duly authorized and validly issued, are fully paid and
  nonassessable and have been issued in compliance with federal and state
  securities laws. None of the outstanding shares of Common Stock were issued in
  violation of any preemptive rights, rights of first refusal or other similar
  rights to subscribe for or purchase securities of the Company. There are no
  authorized or outstanding options, warrants, preemptive rights, rights of
  first refusal or other rights to purchase, or equity or debt securities
  convertible into or exchangeable or exercisable for, any capital stock of the
  Company other than those accurately described in the Prospectus. The
  description of the Company's stock option, stock bonus and other stock plans
  or arrangements, and the options or other rights granted thereunder, set forth
  in the Prospectus accurately and fairly presents the information required to
  be shown with respect to such plans, arrangements, options and rights.
  
        (l) Stock Exchange Listing.   The Common Shares have been approved for
  inclusion on the Nasdaq National Market subject only to official notice of
  issuance.

        (m) Non-Contravention of Existing Instruments; No Further Authorizations
  or Approvals Required.  The Company is not in violation of its charter or by-
  laws or is in default (or, with the giving of notice or lapse of time, would
  be in default) ("Default") under any indenture, mortgage, loan or credit
  agreement, note, contract, franchise, lease or other instrument to which the
  Company is a party or by which it may be bound (including, without limitation,
  any indenture, mortgage, loan or credit agreement, note, contract, franchise,
  lease or other instrument to which the Predecessor, immediately prior to the
  Reincorporation, was a party or by which it may have been bound), or to which
  any of the property or assets of the Company (including, without limitation,
  any property or assets of the Predecessor immediately prior to the
  Reincorporation) is subject (each, an "Existing Instrument"), except for such
  Defaults as would not, individually or in the aggregate, result in a Material
  Adverse Change.  The Company's execution, delivery and performance of this
  Agreement and consummation of the transactions contemplated hereby and by the
  Prospectus (i) have been duly authorized by all necessary corporate action and
  will not result in any violation of the provisions of the charter or by-laws
  of the Company, (ii) will not conflict with or constitute a breach of, or
  Default under, or result in the creation or imposition of any lien, charge or
  encumbrance upon any property or assets of the Company pursuant to, or require
  the consent of any other part to, any Existing Instrument, except for such
  conflicts, breaches, Defaults, liens, charges or encumbrances as would not,
  individually or in the aggregate, result in a Material Adverse Change and
  (iii) will not result in any violation of any law, administrative regulation
  or administrative or court decree applicable to the Company.  No consent,
  approval, authorization or other order of, or registration or filing with, any
  court or other governmental or regulatory authority or agency, is required for
  the Company's execution, delivery and performance of this Agreement and
  consummation of the transactions contemplated hereby and by the Prospectus,
  except such as have been obtained or made by the Company and are in full force
  and effect under the Securities Act, and except for such consents, approvals,
  authorizations, orders of or registrations or filings under applicable state
  securities or blue sky laws and with the National Association of Securities
  Dealers, Inc. (the "NASD").

        (n) No Material Actions or Proceedings.  There are no legal or
  governmental actions, suits or proceedings pending or, to the best of the
  Company's knowledge, threatened (i) against or affecting the Company or the
  Predecessor, (ii) which has as the subject thereof any officer or director of,
  or property owned or leased by, the Company or the Predecessor or

                                       5

 
  (iii) relating to environmental or discrimination matters, where in any such
  case (A) there is a reasonable possibility that such action, suit or
  proceeding might be determined adversely to the Company and (B) any such
  action, suit or proceeding, if so determined adversely, would reasonably be
  expected to result in a Material Adverse Change or adversely affect the
  consummation of the transactions contemplated by this Agreement.  No material
  labor dispute with the employees of the Company exists or, to the best of the
  Company's knowledge, is threatened or imminent.

        (o) Intellectual Property Rights.  The Company owns or possesses
  sufficient trademarks, trade names, patent rights, copyrights, licenses,
  approvals, trade secrets and other similar rights (collectively, "Intellectual
  Property Rights") reasonably necessary to conduct its business as now
  conducted; and the expected expiration of any of such Intellectual Property
  Rights would not result in a Material Adverse Change, except as otherwise
  disclosed in the Prospectus.  Neither the Company nor the Predecessor has
  received any notice of infringement or conflict with asserted Intellectual
  Property Rights of others, which infringement or conflict, if the subject of
  an unfavorable decision, would result in a Material Adverse Change.

        (p) All Necessary Permits, etc.   The Company possesses such valid and
  current certificates, authorizations or permits issued by the appropriate
  state, federal or foreign regulatory agencies or bodies required to conduct
  its business except where the failure to possess such certificates,
  authorizations or permits would not result in a Material Adverse Change, and
  neither the Company nor the Predecessor has received any notice of proceedings
  relating to the revocation or modification of, or non-compliance with, any
  such certificate, authorization or permit which, singly or in the aggregate,
  if the subject of an unfavorable decision, ruling or finding, could result in
  a Material Adverse Change.

         (q) Title to Properties.  The Company has good and marketable title to
  all the properties and assets reflected as owned in the financial statements
  referred to in Section 1(i) above, in each case free and clear of any security
  interests, mortgages, liens, encumbrances, equities, claims and other defects,
  except such as do not materially and adversely affect the value of such
  property and do not materially interfere with the use made or proposed to be
  made of such property by the Company.  The real property, improvements,
  equipment and personal property held under lease by the Company are held under
  valid and enforceable leases, with such exceptions as are not material and do
  not materially interfere with the use made or proposed to be made of such real
  property, improvements, equipment or personal property by the Company.

         (r) Tax Law Compliance.  The Company and the Predecessor have filed all
  necessary federal, state and foreign income and franchise tax returns or have
  properly requested extensions thereof and have paid all taxes shown as due on
  such returns and extensions and, if due and payable, any related or similar
  assessment, fine or penalty levied against either of them.  Through June 30,
  1997, the Company has made adequate charges, accruals and reserves in the
  applicable financial statements referred to in Section 1(i) above in respect
  of all federal, state and foreign income and franchise taxes for all periods
  as to which the tax liability of the Company and the Predecessor have not been
  finally determined.

         (s) Company Not an Investment Company. The Company has been advised of
  the rules and requirements under the Investment Company Act of 1940, as
  amended (the 

                                       6

 
  "Investment Company Act"). The Company is not, and after receipt of payment
  for the Common Shares will not be, an "investment company" within the meaning
  of Investment Company Act and will conduct its business in a manner so that it
  will not become subject to the Investment Company Act.

        (t) Insurance.  The Company is insured by recognized, financially sound
  and reputable institutions with policies in such amounts and with such
  deductibles and covering such risks as are generally deemed adequate and
  customary for its business including, but not limited to, policies covering
  real and personal property owned or leased by the Company against theft,
  damage, destruction and acts of vandalism.  The Company has no reason to
  believe that it will not be able (i) to renew its existing insurance coverage
  as and when such policies expire or (ii) to obtain comparable coverage from
  similar institutions as may be necessary or appropriate to conduct its
  business as now conducted and at a cost that would not result in a Material
  Adverse Change.  Neither the Company nor the Predecessor have been denied any
  insurance coverage which either of them have sought or for which either of
  them have applied.

         (u) No Price Stabilization or Manipulation.  The Company has not taken
  and will not take, directly or indirectly, any action designed to or that
  might be reasonably expected to cause or result in stabilization or
  manipulation of the price of the Common Stock to facilitate the sale or resale
  of the Common Shares.

        (v) Related Party Transactions.  There are no business relationships or
  related-party transactions involving the Company, the Predecessor or any other
  person required to be described in the Prospectus which have not been
  described as required.

        (w) Reincorporation.  The execution an delivery of the Agreement and
  Plan of Merger dated as of [September __, 1997] (the "Merger Agreement")
  between the Company and the Predecessor, effecting the reincorporation of the
  Predecessor under the laws of the State of Delaware, was duly authorized by
  all necessary corporate action on the part of each of the Company and the
  Predecessor.  Each of the Company and the Predecessor had all corporate power
  and authority to execute and deliver the Merger Agreement and the Certificate
  of Merger between the Company and the Predecessor complying with Section 251
  of the Delaware General Corporation Law and referencing the Merger Agreement
  (the "Certificate of Merger"), to file the Certificate of Merger with the
  Secretary of State of California and the Secretary of State of Delaware and to
  consummate the reincorporation contemplated by the Merger Agreement, and the
  Merger Agreement at the time of execution and filing constituted a valid and
  binding obligation of each of the Company and the Predecessor, enforceable in
  accordance with its terms.  The merger of the Predecessor with and into the
  Company has been consummated in compliance with applicable law.  The Company
  has succeeded to all of the rights, privileges, powers and franchises, and is
  subject to all of the restrictions, disabilities and duties, of the
  Predecessor.  The Company has succeeded to all of the contract rights of the
  Predecessor, and all required consents with respect to such contracts have
  been obtained.  All of the previously outstanding shares of capital stock of
  the Predecessor have been converted into that number of shares of capital
  stock of the Company having the same rights, preferences and privileges
  (except for differences resulting from applicable law and applicable bylaws)
  as described in the Prospectus.  All of the previously outstanding options and
  warrants of the Predecessor are exercisable for that number of shares of
  Common Stock of the Company as described in the 

                                       7

 
  Prospectus. The consummation of the Reincorporation did 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 constitute a breach of or
  default under), any Existing Instrument. The consummation of the
  Reincorporation did not and will not conflict with, or result in a violation
  of, any federal, state, local or foreign law, regulation or rule or any
  decree, judgment or order applicable to the Company, or immediately prior to
  the Reincorporation, the Predecessor, the result of which could have a
  Material Adverse Effect. The issuance of capital stock by the Company in the
  Reincorporation was in compliance with all applicable state securities or blue
  sky laws and was exempt from registration under the Securities Act.

        (x) No Unlawful Contributions or Other Payments.  Neither the Company,
  the Predecessor, nor, to the best of the Company's knowledge, any employee or
  agent of the Company or the Predecessor, has made any contribution or other
  payment to any official of, or candidate for, any federal, state or foreign
  office in violation of any law or of the character required to be disclosed in
  the Prospectus.

         (y) Company's Accounting System.  The Company maintains a system of
  accounting controls sufficient to provide reasonable assurances that
  (i) transactions are executed in accordance with management's general or
  specific authorization; (ii) transactions are recorded as necessary to permit
  preparation of financial statements in conformity with generally accepted
  accounting principles and to maintain accountability for assets; (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 existing assets at reasonable intervals and appropriate action
  is taken with respect to any differences.
 
        (z) Compliance with Environmental Laws.  Except as would not,
  individually or in the aggregate, result in a Material Adverse Change (i) the
  Company is not in violation of any federal, state, local or foreign law or
  regulation relating to pollution or protection of human health or the
  environment (including, without limitation, ambient air, surface water,
  groundwater, land surface or subsurface strata) or wildlife, including without
  limitation, laws and regulations relating to emissions, discharges, releases
  or threatened releases of chemicals, pollutants, contaminants, wastes, toxic
  substances, hazardous substances, petroleum and petroleum products
  (collectively, "Materials of Environmental Concern"), or otherwise relating to
  the manufacture, processing, distribution, use, treatment, storage, disposal,
  transport or handling of Materials of Environment Concern (collectively,
  "Environmental Laws"), which violation includes, but is not limited to,
  noncompliance with any permits or other governmental authorizations required
  for the operation of the business of the Company under applicable
  Environmental Laws, or noncompliance with the terms and conditions thereof,
  nor has the Company or the Predecessor received any written communication,
  whether from a governmental authority, citizens group, employee or otherwise,
  that alleges that the Company is or the Predecessor was immediately prior to
  the Reincorporation in violation of any Environmental Law; (ii) there is no
  claim, action or cause of action filed with a court or governmental authority,
  no investigation with respect to which the Company or the Predecessor has
  received written notice, and no written notice by any person or entity
  alleging potential liability for investigatory costs, cleanup costs,
  governmental responses costs, natural resources damages, property damages,
  personal injuries, attorneys' fees or penalties arising out of, based on or
  resulting from the presence, or release into the environment, of any Material
  of Environmental Concern at any location owned, leased or operated by the
  Company, now or in the past (collectively, "Environmental 

                                       8

 
  Claims"), pending or, to the best of the Company's knowledge, threatened
  against the Company or any person or entity whose liability for any
  Environmental Claim the Company has retained or assumed either contractually
  or by operation of law; and (iii) to the best of the Company's knowledge,
  there are no past or present actions, activities, circumstances, conditions,
  events or incidents, including, without limitation, the release, emission,
  discharge, presence or disposal of any Material of Environmental Concern, that
  reasonably could result in a violation of any Environmental Law or form the
  basis of a potential Environmental Claim against the Company or against any
  person or entity whose liability for any Environmental Claim the Company has
  retained or assumed either contractually or by operation of law.

        (aa) Periodic Review of Costs of Environmental Compliance.  In the
  ordinary course of its business, the Company conducts and the Predecessor
  conducted periodic reviews of the effect of Environmental Laws on the
  business, operations and properties of the Company.  On the basis of such
  review and the amount of its established reserves, the Company has reasonably
  concluded that such associated costs and liabilities would not, individually
  or in the aggregate, result in a Material Adverse Change.

        (bb) ERISA Compliance.  The Company and any "employee benefit plan" (as
  defined under the Employee Retirement Income Security Act of 1974, as amended,
  and the regulations and published interpretations thereunder (collectively,
  "ERISA")) established or maintained by the Company or their "ERISA Affiliates"
  (as defined below) are in compliance in all material respects with ERISA.
  "ERISA Affiliate" means, with respect to the Company, any member of any group
  of organizations described in Sections 414(b),(c),(m) or (o) of the Internal
  Revenue Code of 1986, as amended, and the regulations and published
  interpretations thereunder (the "Code") of which the Company is a member.  No
  "reportable event" (as defined under ERISA) has occurred or is reasonably
  expected to occur with respect to any "employee benefit plan" established or
  maintained by the Company or any of their ERISA Affiliates.  No "employee
  benefit plan" established or maintained by the Company or any of their ERISA
  Affiliates, if such "employee benefit plan" were terminated, would have any
  "amount of unfunded benefit liabilities" (as defined under ERISA).  Neither
  the Company nor any of their ERISA Affiliates has incurred or reasonably
  expects to incur any material liability under (i) Title IV of ERISA with
  respect to termination of, or withdrawal from, any "employee benefit plan" or
  (ii) Sections 412, 4971, 4975 or 4980B of the Code.  Each "employee benefit
  plan" established or maintained by the Company or any of its ERISA Affiliates
  that is intended to be qualified under Section 401(a) of the Code has received
  a favorable determination letter from the Internal Revenue Service and to the
  Company's knowledge nothing has occurred, whether by action or failure to act,
  which would cause the loss of such qualification.

          Any certificate signed by an officer of the Company and delivered to
the Representatives or to counsel for the Underwriters shall be deemed to be a
representation and warranty by the Company to each Underwriter as to the matters
set forth therein.

          SECTION 2.  PURCHASE, SALE AND DELIVERY OF THE COMMON SHARES.

          The Firm Common Shares.  The Company agrees to issue and sell to the
several Underwriters the Firm Common Shares upon the terms herein set forth.  On
the basis of the 

                                       9

 
representations, warranties and agreements herein contained, and upon the terms
but subject to the conditions herein set forth, the Underwriters agree,
severally and not jointly, to purchase from the Company the respective number of
Firm Common Shares set forth opposite their names on Schedule A. The purchase
                                                     ----------
price per Firm Common Share to be paid by the several Underwriters to the
Company shall be $[___] per share.

          The First Closing Date.  Delivery of certificates for the Firm Common
Shares to be purchased by the Underwriters and payment therefor shall be made at
the offices of Montgomery Securities, 600 Montgomery Street, San Francisco,
California (or such other place as may be agreed to by the Company and the
Representatives) at 6:00 a.m. San Francisco time, on [insert the fourth full
business day after the date of this Agreement] or such other time and date not
later than 10:30 a.m. San Francisco time, on [insert the date ten business days
following the original contemplated First Closing Date] as the Representatives
shall designate by notice to the Company (the time and date of such closing are
called the "First Closing Date").  The Company hereby acknowledges that
circumstances under which the Representatives may provide notice to postpone the
First Closing Date as originally scheduled include, but are in no way limited
to, any determination by the Company or the Representatives to recirculate to
the public copies of an amended or supplemented Prospectus or a delay as
contemplated by the provisions of Section 10.

          The Optional Common Shares; the Second Closing Date.  In addition, on
the basis of the representations, warranties and agreements herein contained,
and upon the terms but subject to the conditions herein set forth, the Company
hereby grants an option to the several Underwriters to purchase, severally and
not jointly, up to an aggregate of 375,000 Optional Common Shares from the
Company at the purchase price per share to be paid by the Underwriters for the
Firm Common Shares.  The option granted hereunder is for use by the Underwriters
solely in covering any over-allotments in connection with the sale and
distribution of the Firm Common Shares.  The option granted hereunder may be
exercised at any time (but not more than once) upon notice by the
Representatives to the Company, which notice may be given at any time within
30 days from the date of this Agreement.  Such notice shall set forth (i) the
aggregate number of Optional Common Shares as to which the Underwriters are
exercising the option, (ii) the names and denominations in which the
certificates for the Optional Common Shares are to be registered and (iii) the
time, date and place at which such certificates will be delivered (which time
and date may be simultaneous with, but not earlier than, the First Closing Date
if such notice is provided at least two days prior to the First Closing Date;
and in such case the term "First Closing Date" shall refer to the time and date
of delivery of certificates for the Firm Common Shares and the Optional Common
Shares).  Such time and date of delivery, if subsequent to the First Closing
Date, is called the "Second Closing Date" and shall be determined by the
Representatives and shall not be earlier than three nor later than five full
business days after delivery of such notice of exercise.  If any Optional Common
Shares are to be purchased, each Underwriter agrees, severally and not jointly,
to purchase the number of Optional Common Shares (subject to such adjustments to
eliminate fractional shares as the Representatives may determine) that bears the
same proportion to the total number of Optional Common Shares to be purchased as
the number of Firm Common Shares set forth on Schedule A opposite the name of
                                              ----------                     
such Underwriter bears to the total number of Firm Common Shares.  The
Representatives may cancel the option at any time prior to its expiration by
giving written notice of such cancellation to the Company.

                                      10

 
          Public Offering of the Common Shares.  The Representatives hereby
advise the Company that the Underwriters intend to offer for sale to the public,
as described in the Prospectus, their respective portions of the Common Shares
as soon after this Agreement has been executed and the Registration Statement
has been declared effective as the Representatives, in their sole judgment, have
determined is advisable and practicable.

          Payment for the Common Shares.  Payment for the Common Shares shall be
made at the First Closing Date (and, if applicable, at the Second Closing Date)
by wire transfer of immediately available funds to the order of the Company.

          It is understood that the Representatives have been authorized, for
their own respective accounts and the accounts of the several Underwriters, to
accept delivery of and receipt for, and make payment of the purchase price for,
the Firm Common Shares and any Optional Common Shares the Underwriters have
agreed to purchase.  Except as specifically set forth in Section 10 hereof,
Montgomery Securities, individually and not as a Representative of the
Underwriters, may (but shall not be obligated to) make payment for any Common
Shares to be purchased by any Underwriter whose funds shall not have been
received by the Representatives by the First Closing Date or the Second Closing
Date, as the case may be, for the account of such Underwriter, and any such
payment shall not relieve such Underwriter from any of its obligations under
this Agreement.

          Delivery of the Common Shares.  The Company shall deliver, or cause to
be delivered, to the Representatives for the accounts of the several
Underwriters certificates for the Firm Common Shares at the First Closing Date,
against the irrevocable release of a wire transfer of immediately available
funds for the amount of the purchase price therefor.  The Company shall also
deliver, or cause to be delivered, to the Representatives for the accounts of
the several Underwriters, certificates for the Optional Common Shares the
Underwriters have agreed to purchase at the First Closing Date or the Second
Closing Date, as the case may be, against the irrevocable release of a wire
transfer of immediately available funds for the amount of the purchase price
therefor.  The certificates for the Common Shares shall be in definitive form
and registered in such names and denominations as the Representatives shall have
requested at least two full business days prior to the First Closing Date (or
the Second Closing Date, as the case may be) and shall be made available for
inspection on the business day preceding the First Closing Date (or the Second
Closing Date, as the case may be) at a location in New York City as the
Representatives may designate.  Time shall be of the essence, and delivery at
the time and place specified in this Agreement is a further condition to the
obligations of the Underwriters.

          Delivery of Prospectus to the Underwriters.  Not later than 12:00 p.m.
on the second business day following the date the Common Shares are released by
the Underwriters for sale to the public, the Company shall delivery or cause to
be delivered copies of the Prospectus in such quantities and at such places as
the Representatives shall request.

          SECTION 3.  ADDITIONAL COVENANTS OF THE COMPANY.

          The Company further covenants and agrees with each Underwriter as
follows:

        (a) Representatives' Review of Proposed Amendments and Supplements.
  During such period beginning on the date hereof and ending on the later of the
  First Closing Date or such date, as in the opinion of counsel for the
  Underwriters, the Prospectus is no longer 

                                      11

 
  required by law to be delivered in connection with sales by an Underwriter or
  dealer (the "Prospectus Delivery Period"), prior to amending or supplementing
  the Registration Statement (including any registration statement filed under
  Rule 462(b) under the Securities Act) or the Prospectus, the Company shall
  furnish to each Representative for review a copy of each such proposed
  amendment or supplement, and the Company shall not file any such proposed
  amendment or supplement to which any Representative reasonably objects.

        (b) Securities Act Compliance.  After the date of this Agreement, the
  Company shall promptly advise the Representatives in writing (i) of the
  receipt of any comments of, or requests for additional or supplemental
  information from, the Commission, (ii) of the time and date of any filing of
  any post-effective amendment to the Registration Statement or any amendment or
  supplement to any preliminary prospectus or the Prospectus, (iii) of the time
  and date that any post-effective amendment to the Registration Statement
  becomes effective and (iv) of the issuance by the Commission of any stop order
  suspending the effectiveness of the Registration Statement or any post-
  effective amendment thereto or of any order preventing or suspending the use
  of any preliminary prospectus or the Prospectus, or, within two years of the
  date of this Agreement, of any proceedings to remove, suspend or terminate
  from listing or quotation the Common Stock from any securities exchange upon
  which it is listed for trading or included or designated for quotation, or of
  the threatening or initiation of any proceedings for any of such purposes.  If
  the Commission shall enter any such stop order at any time, the Company will
  use its best efforts to obtain the lifting of such order at the earliest
  possible moment.  Additionally, the Company agrees that it shall comply with
  the provisions of Rules 424(b), 430A and 434, as applicable, under the
  Securities Act and will use its reasonable efforts to confirm that any filings
  made by the Company under such Rule 424(b) were received in a timely manner by
  the Commission.
 
        (c) Amendments and Supplements to the Prospectus and Other Securities
  Act Matters.  If, during the Prospectus Delivery Period, any event shall occur
  or condition exist as a result of which it is necessary to amend or supplement
  the Prospectus in order to make the statements therein, in the light of the
  circumstances when the Prospectus is delivered to a purchaser, not misleading,
  or if in the reasonable opinion of the Representatives or counsel for the
  Underwriters it is otherwise necessary to amend or supplement the Prospectus
  to comply with law, the Company agrees to promptly prepare (subject to
  Section 3(A)(a) hereof), file with the Commission and furnish at its own
  expense to the Underwriters and to dealers, amendments or supplements to the
  Prospectus so that the statements in the Prospectus as so amended or
  supplemented will not, in the light of the circumstances when the Prospectus
  is delivered to a purchaser, be misleading or so that the Prospectus, as
  amended or supplemented, will comply with law.
 
        (d) Copies of any Amendments and Supplements to the Prospectus.  The
  Company agrees to furnish the Representatives, without charge, during the
  Prospectus Delivery Period, as many copies of the Prospectus and any
  amendments and supplements thereto as the Representatives may request.
 
        (e) Blue Sky Compliance.  The Company shall cooperate with the
  Representatives and counsel for the Underwriters to qualify or register the
  Common Shares for sale under (or obtain exemptions from the application of)
  the state securities or blue sky laws or Canadian provincial securities laws
  of those jurisdictions designated by the Representatives, shall comply with
  such laws and shall continue such qualifications, registrations and exemptions

                                      12

 
  in effect so long as required for the distribution of the Common Shares.  The
  Company shall not be required to qualify as a foreign corporation or to take
  any action that would subject it to general service of process in any such
  jurisdiction where it is not presently qualified or where it would be subject
  to taxation as a foreign corporation.  The Company will advise the
  Representatives promptly of the suspension of the qualification or
  registration of (or any such exemption relating to) the Common Shares for
  offering, sale or trading in any jurisdiction or any initiation or, to its
  knowledge, any threat of any proceeding for any such purpose, and in the event
  of the issuance of any order suspending such qualification, registration or
  exemption, the Company shall use its best efforts to obtain the withdrawal
  thereof at the earliest possible moment.
 
        (f) Use of Proceeds.  The Company shall apply the net proceeds from the
  sale of the Common Shares sold by it substantially in the manner described
  under the caption "Use of Proceeds" in the Prospectus.
 
        (g) Transfer Agent.  The Company shall engage and maintain, at its
  expense, a registrar and transfer agent for the Common Stock.

        (h) Earnings Statement.  As soon as practicable, the Company will make
  generally available to its security holders and to the Representatives an
  earnings statement (which need not be audited) covering the twelve-month
  period ending [September 30, 1998] that satisfies the provisions of Section
  11(a) of the Securities Act.
 
        (i) Periodic Reporting Obligations.  During the Prospectus Delivery
  Period the Company shall file, on a timely basis, with the Commission and the
  Nasdaq National Market all reports and documents required to be filed under
  the Exchange Act.  Additionally, the Company shall file with the Commission
  all reports on Form SR as may be required under Rule 463 under the Securities
  Act.
 
        (j) Agreement Not To Offer or Sell Additional Securities.  During the
  period of 180 days following the date of the Prospectus, the Company will not,
  without the prior written consent of Montgomery Securities (which consent may
  be withheld at the sole discretion of Montgomery Securities), directly or
  indirectly, sell, offer, contract or grant any option to sell, pledge,
  transfer or establish an open "put equivalent position" within the meaning of
  Rule 16a-1(h) under the Exchange Act, or otherwise dispose of or transfer, or
  announce the offering of, or file any registration statement under the
  Securities Act in respect of, any shares of Common Stock, options or warrants
  to acquire shares of the Common Stock or securities exchangeable or
  exercisable for or convertible into shares of Common Stock (other than as
  contemplated by this Agreement with respect to the Common Shares); provided,
  however, that the Company may issue shares of its Common Stock or options to
  purchase its Common Stock, or Common Stock upon exercise of options, pursuant
  to any stock option, stock purchase, stock bonus or other stock plan or
  arrangement described in the Prospectus, but only if the holders of such
  shares, options, or shares issued upon exercise of such options, agree in
  writing not to sell, offer, dispose of or otherwise transfer any such shares,
  or options during such 180 day period without the prior written consent of the
  Company.  Notwithstanding the foregoing sentence, the Company need not obtain
  agreements regarding the sale, offer, disposition or other transfer of shares
  of the Company's Common Stock issued pursuant to the Company's Employee Stock
  Purchase Plan.

                                      13

 
       (k) Agreement Not To Release Lock-Ups.  During the period of 180 days
  following the date of the Prospectus, the Company will not, without the
  prior written consent of Montgomery Securities (which consent may be
  withheld at the sole discretion of Montgomery Securities), release, waive,
  amend or modify Section 2.13 of the Company's Amended and Restated
  Investors' Rights Agreement dated May 23, 1997, Section 7(b)(ii) of the
  Company's standard Incentive Stock Option Stock Purchase Agreement with
  optionees, Section 7(a)(ii) of the Company's standard Non-statutory Stock
  Option Stock Purchase Agreement with optionees, or any contractual provision
  between the Company and any third party which limits such third party's
  rights, directly or indirectly, to sell, offer, contract or grant any option
  to sell, pledge, transfer or establish an open "put equivalent position"
  within the meaning of Rule 16a-1(h) under the Exchange Act, or otherwise
  dispose of or transfer, or announce the offering of any shares of Common
  Stock, options or warrants to acquire shares of the Common Stock or
  securities exchangeable or exercisable for or convertible into shares of
  Common Stock.

        (l) Future Reports to the Representatives.  During the period of three
  years hereafter the Company will furnish to the Representatives at: Montgomery
  Securities, 600 Montgomery Street, San Francisco, CA 94111 Attention: Michael
  Dovey; and Hambrecht & Quist, 230 Park Avenue, New York, NY 10169, Attention:
  Dennis J. Purcell: (i) as soon as practicable after the end of each fiscal
  year, copies of the Annual Report of the Company containing the balance sheet
  of the Company as of the close of such fiscal year and statements of income,
  stockholders' equity and cash flows for the year then ended and the opinion
  thereon of the Company's independent public or certified public accountants;
  (ii) as soon as practicable after the filing thereof, copies of each proxy
  statement, Annual Report on Form 10-K, Quarterly Report on Form 10-Q, Current
  Report on Form 8-K or other report filed by the Company with the Commission,
  the NASD or any securities exchange; and (iii) as soon as available, copies of
  any report or communication of the Company mailed generally to holders of its
  capital stock.

          SECTION 4.  PAYMENT OF EXPENSES.  The Company agrees to pay all costs,
fees and expenses incurred in connection with the performance of its obligations
hereunder and in connection with the transactions contemplated hereby, including
without limitation (i) all expenses incident to the issuance and delivery of the
Common Shares (including all printing and engraving costs), (ii) all fees and
expenses of the registrar and transfer agent of the Common Stock, (iii) all
necessary issue, transfer and other stamp taxes in connection with the issuance
and sale of the Common Shares to the Underwriters, (iv) all fees and expenses of
the Company's counsel, independent public or certified pubic accountants and
other advisors, (v) all costs and expenses incurred in connection with the
preparation, printing, filing, shipping and distribution of the Registration
Statement (including financial statements, exhibits, schedules, consents and
certificates of experts), each preliminary prospectus and the Prospectus, and
all amendments and supplements thereto, and this Agreement, (vi) all filing
fees, attorneys' fees and expenses incurred by the Company or the Underwriters
in connection with qualifying or registering (or obtaining exemptions from the
qualification or registration of) all or any part of the Common Shares for offer
and sale under the state securities or blue sky laws or the provincial
securities laws of Canada, and, if requested by the Representatives, preparing
and printing a "Blue Sky Survey" or memorandum, and any supplements thereto,
advising the Underwriters of such qualifications, registrations and exemptions,
(vii) the filing fees incident to, and the reasonable fees and expenses of
counsel for the Underwriters in connection with, the NASD's review and approval
of the Underwriters' participation in the offering and distribution of the
Common Shares, (viii) the fees and expenses associated with listing the Common
Shares on the Nasdaq 

                                      14

 
National Market and (ix) all other fees, costs and expenses referred to in Item
13 of Part II of the Registration Statement. Except as provided in this Section
4, Section 6, Section 8 and Section 9 hereof, the Underwriters shall pay their
own expenses, including the fees and disbursements of their counsel.

          SECTION 5.  CONDITIONS OF THE OBLIGATIONS OF THE UNDERWRITERS.  The
obligations of the several Underwriters to purchase and pay for the Common
Shares as provided herein on the First Closing Date and, with respect to the
Optional Common Shares, the Second Closing Date, shall be subject to the
accuracy of the representations and warranties on the part of the Company set
forth in Section 1 hereof as of the date hereof and as of the First Closing Date
as though then made and, with respect to the Optional Common Shares, as of the
Second Closing Date as though then made, to the timely performance by the
Company of its covenants and other obligations hereunder, and to each of the
following additional conditions:

        (a) Accountants' Comfort Letter. On the date hereof, the Representatives
  shall have received from Ernst & Young LLP, independent public or certified
  public accountants for the Company, a letter dated the date hereof addressed
  to the Underwriters, in form and substance satisfactory to the
  Representatives, containing statements and information of the type ordinarily
  included in accountant's "comfort letters" to underwriters, delivered
  according to Statement of Auditing Standards No. 72 (or any successor
  bulletin), with respect to the audited and unaudited financial statements and
  certain financial information contained in the Registration Statement and the
  Prospectus (and the Representatives shall have received an additional [___]
  conformed copies of such accountants' letter for each of the several
  Underwriters).

        (b) Compliance with Registration Requirements; No Stop Order; No
  Objection from NASD.  For the period from and after effectiveness of this
  Agreement and prior to the First Closing Date and, with respect to the
  Optional Common Shares, the Second Closing Date:
 
          (i) the Company shall have filed the Prospectus with the Commission
     (including the information required by Rule 430A under the Securities Act)
     in the manner and within the time period required by Rule 424(b) under the
     Securities Act; or the Company shall have filed a post-effective amendment
     to the Registration Statement containing the information required by such
     Rule 430A, and such post-effective amendment shall have become effective;
     or, if the Company elected to rely upon Rule 434 under the Securities Act
     and obtained the Representatives' consent thereto, the Company shall have
     filed a Term Sheet with the Commission in the manner and within the time
     period required by such Rule 424(b);
 
          (ii) no stop order suspending the effectiveness of the Registration
     Statement, any Rule 462(b) Registration Statement, or any post-effective
     amendment to the Registration Statement, shall be in effect and no
     proceedings for such purpose shall have been instituted or threatened by
     the Commission; and
 
          (iii) the NASD shall have raised no objection to the fairness and
     reasonableness of the underwriting terms and arrangements.

       (c) No Material Adverse Change. For the period from and after the date of
  this Agreement and prior to the First Closing Date and, with respect to the
  Optional Common 

                                      15

 
  Shares, the Second Closing Date, in the judgment of the Representatives there
  shall not have occurred any Material Adverse Change.

        (d) Opinion of Counsel for the Company.  On each of the First Closing
  Date and the Second Closing Date the Representatives shall have received the
  opinion of Cooley Godward LLP, counsel for the Company, dated as of such
  Closing Date, the form of which is attached as Exhibit A (and the
                                                 ---------         
  Representatives shall have received an additional [___] conformed copies of
  such counsel's legal opinion for each of the several Underwriters).

        (e) Opinion of Intellectual Property Counsel for the Company.  On each
  of the First Closing Date and the Second Closing Date the Representatives
  shall have received the opinion of McDonnell, Boehnen, Hulbert & Berghoff,
  Ltd., intellectual property counsel for the Company, dated as of such Closing
  Date, the form of which is attached as Exhibit B (and the Representatives
                                         ---------                         
  shall have received an additional [___] conformed copies of such counsel's
  legal opinion for each of the several Underwriters).

        (f) Opinion of Counsel for the Underwriters.  On each of the First
  Closing Date and the Second Closing Date the Representatives shall have
  received the opinion of Gunderson Dettmer Stough Villeneuve Franklin &
  Hachigian, LLP, counsel for the Underwriters, dated as of such Closing Date,
  with respect to the matters set forth in paragraphs [[(i), (vi) (with respect
  to subparagraph (i) only), (vii) (with respect to subparagraph (i) only),
  (viii), (ix) and (xii) (with respect to the captions "Description of Capital
  Stock" and "Underwriting" under subparagraph (i) only)] and [the next-to-last
  paragraph] of Exhibit A (and the Representatives shall have received an
                ---------                                                
  additional [___] conformed copies of such counsel's legal opinion for each of
  the several Underwriters).

        (g) Officers' Certificate.  On each of the First Closing Date and the
  Second Closing Date the Representatives shall have received a written
  certificate executed by the Chairman of the Board, Chief Executive Officer or
  President of the Company and the Chief Financial Officer or Chief Accounting
  Officer of the Company, dated as of such Closing Date, to the effect set forth
  in subsections (b)(ii) of this Section 5, and further to the effect that:

           (i) for the period from and after the date of this Agreement and
     prior to such Closing Date, there has not occurred any Material Adverse
     Change;

          (ii) the representations, warranties and covenants of the Company set
     forth in Section 1 of this Agreement are true and correct with the same
     force and effect as though expressly made on and as of such Closing Date;
     and
 
          (iii)  the Company has complied with all the agreements and satisfied
     all the conditions on its part to be performed or satisfied at or prior to
     such Closing Date.

       (h) Bring-down Comfort Letter.  On each of the First Closing Date and the
  Second Closing Date the Representatives shall have received from Ernst & Young
  LLP, independent public or certified public accountants for the Company, a
  letter dated such date, in form and substance satisfactory to the
  Representatives, to the effect that they reaffirm the statements made in the
  letter furnished by them pursuant to subsection (a) of this Section 5, except
  that the specified date referred to therein for the carrying out of procedures
  shall be no more than three business days prior to the First Closing Date or
  Second Closing Date, as the case may 

                                      16

 
  be (and the Representatives shall have received an additional [___] conformed
  copies of such accountants' letter for each of the several Underwriters).

        (i) Lock-Up Agreement from Certain Stockholders of the Company.  On the
  date hereof, the Company shall have furnished to the Representatives an
  agreement in the form of Exhibit C hereto from each director, officer and
                           ---------                                       
  beneficial owner of Common Stock of the Company holding more than [1.0]% of
  the outstanding securities of the Company, and such agreement shall be in full
  force and effect on each of the First Closing Date and the Second Closing
  Date.

        (j) Additional Documents.  On or before each of the First Closing Date
  and the Second Closing Date, the Representatives and counsel for the
  Underwriters shall have received such information, documents and opinions as
  they may reasonably require for the purposes of enabling them to pass upon the
  issuance and sale of the Common Shares as contemplated herein, or in order to
  evidence the accuracy of any of the representations and warranties, or the
  satisfaction of any of the conditions or agreements, herein contained.

     If any condition specified in this Section 5 is not satisfied when and as
required to be satisfied, this Agreement may be terminated by the
Representatives by notice to the Company at any time on or prior to the First
Closing Date and, with respect to the Optional Common Shares, at any time prior
to the Second Closing Date, which termination shall be without liability on the
part of any party to any other party, except that Section 4, Section 6,
Section 8 and Section 9 shall at all times be effective and shall survive such
termination.

          SECTION 6.  REIMBURSEMENT OF UNDERWRITERS' EXPENSES.  If this
Agreement is terminated by the Representatives pursuant to Section 5, Section 7
or Section 11, or if the sale to the Underwriters of the Common Shares on the
First Closing Date is not consummated because of any refusal, inability or
failure on the part of the Company to perform any agreement herein or to comply
with any provision hereof, the Company agrees to reimburse the Representatives
and the other Underwriters (or such Underwriters as have terminated this
Agreement with respect to themselves), severally, upon demand for all out-of-
pocket expenses that shall have been reasonably incurred by the Representatives
and the Underwriters in connection with the proposed purchase and the offering
and sale of the Common Shares, including but not limited to fees and
disbursements of counsel, printing expenses, travel expenses, postage, facsimile
and telephone charges.

          SECTION 7.  EFFECTIVENESS OF THIS AGREEMENT.

          This Agreement shall not become effective until the later of (i) the
execution of this Agreement by the parties hereto and (ii) notification by the
Commission to the Company and the Representatives of the effectiveness of the
Registration Statement under the Securities Act.

          Prior to such effectiveness of the Registration Statement, this
Agreement may be terminated by any party by notice to each of the other parties
hereto, and any such termination shall be without liability on the part of
(a) the Company to any Underwriter, except that the Company shall be obligated
to reimburse the expenses of the Representatives and the Underwriters pursuant
to Sections 4 and 6 hereof, (b) of any Underwriter to the Company, or 

                                      17

 
(c) of any party hereto to any other party except that the provisions of Section
8 and Section 9 shall at all times be effective and shall survive such
termination.


          SECTION 8.  INDEMNIFICATION.

        (a) Indemnification of the Underwriters.  The Company agrees to
  indemnify and hold harmless each Underwriter, its officers and employees, and
  each person, if any, who controls any Underwriter within the meaning of the
  Securities Act and the Exchange Act against any loss, claim, damage, liability
  or expense, as incurred, to which such Underwriter or such controlling person
  may become subject, under the Securities Act, the Exchange Act or other
  federal or state statutory law or regulation, or at common law or otherwise
  (including in settlement of any litigation, if such settlement is effected
  with the written consent of the Company), insofar as such loss, claim, damage,
  liability or expense (or actions in respect thereof as contemplated below)
  arises out of or is based (i) upon any untrue statement or alleged untrue
  statement of a material fact contained in the Registration Statement, or any
  amendment thereto, including any information deemed to be a part thereof
  pursuant to Rule 430A or Rule 434 under the Securities Act, or the omission or
  alleged omission therefrom of a material fact required to be stated therein or
  necessary to make the statements therein not misleading; or (ii) upon any
  untrue statement or alleged untrue statement of a material fact contained in
  any preliminary prospectus or the Prospectus (or any amendment or supplement
  thereto), or the omission or alleged omission therefrom of a material fact
  necessary in order to make the statements therein, in the light of the
  circumstances under which they were made, not misleading; or (iii) in whole or
  in part upon any inaccuracy in the representations and warranties of the
  Company contained herein; or (iv) in whole or in part upon any failure of the
  Company to perform its obligations hereunder or under law; or (v) any act or
  failure to act or any alleged act or failure to act by any Underwriter in
  connection with, or relating in any manner to, the Common Stock or the
  offering contemplated hereby, and which is included as part of or referred to
  in any loss, claim, damage, liability or action arising out of or based upon
  any matter covered by clause (i) or (ii) above, provided that the Company
  shall not be liable under this clause (v) to the extent that a court of
  competent jurisdiction shall have determined by a final judgment that such
  loss, claim, damage, liability or action resulted directly from any such acts
  or failures to act undertaken or omitted to be taken by such Underwriter
  through its bad faith or willful misconduct; and to reimburse each Underwriter
  and each such controlling person for any and all expenses (including the fees
  and disbursements of counsel chosen by Montgomery Securities) as such expenses
  are reasonably incurred by such Underwriter or such controlling person in
  connection with investigating, defending, settling, compromising or paying any
  such loss, claim, damage, liability, expense or action; provided, however,
  that the foregoing indemnity agreement shall not apply to any loss, claim,
  damage, liability or expense to the extent, but only to the extent, arising
  out of or based upon any untrue statement or alleged untrue statement or
  omission or alleged omission made in reliance upon and in conformity with
  written information furnished to the Company by the Representatives expressly
  for use in the Registration Statement, any preliminary prospectus or the
  Prospectus (or any amendment or supplement thereto); and provided, further,
  that with respect to any preliminary prospectus, the foregoing indemnity
  agreement shall not inure to the benefit of any Underwriter from whom the
  person asserting any loss, claim, damage, liability or expense purchased
  Common Shares, or any person controlling such Underwriter, if copies of the
  Prospectus were timely delivered to the Underwriter pursuant to Section 2 and
  a copy of 

                                      18

 
  the Prospectus (as then amended or supplemented if the Company shall have
  furnished any amendments or supplements thereto) was not sent or given by or
  on behalf of such Underwriter to such person, if required by law so to have
  been delivered, at or prior to the written confirmation of the sale of the
  Common Shares to such person, and if the Prospectus (as so amended or
  supplemented) would have cured the defect giving rise to such loss, claim,
  damage, liability or expense. The indemnity agreement set forth in this
  Section 8(a) shall be in addition to any liabilities that the Company may
  otherwise have.

        (b) Indemnification of the Company, its Directors and Officers.  Each
  Underwriter agrees, severally and not jointly, to indemnify and hold harmless
  the Company, each of its directors, each of its officers who signed the
  Registration Statement and each person, if any, who controls the Company
  within the meaning of the Securities Act or the Exchange Act, against any
  loss, claim, damage, liability or expense, as incurred, to which the Company,
  or any such director, officer or controlling person may become subject, under
  the Securities Act, the Exchange Act, or other federal or state statutory law
  or regulation, or at common law or otherwise (including in settlement of any
  litigation, if such settlement is effected with the written consent of such
  Underwriter), insofar as such loss, claim, damage, liability or expense (or
  actions in respect thereof as contemplated below) arises out of or is based
  upon any untrue or alleged untrue statement of a material fact contained in
  the Registration Statement, any preliminary prospectus or the Prospectus (or
  any amendment or supplement thereto), or arises out of or is based upon the
  omission or alleged omission to state therein a material fact required to be
  stated therein or necessary to make the statements therein not misleading, in
  each case to the extent, but only to the extent, that such untrue statement or
  alleged untrue statement or omission or alleged omission was made in the
  Registration Statement, any preliminary prospectus, the Prospectus (or any
  amendment or supplement thereto), in reliance upon and in conformity with
  written information furnished to the Company by the Representatives expressly
  for use therein; and to reimburse the Company, or any such director, officer
  or controlling person for any legal and other expense reasonably incurred by
  the Company, or any such director, officer or controlling person in connection
  with investigating, defending, settling, compromising or paying any such loss,
  claim, damage, liability, expense or action.  The Company hereby acknowledges
  that the only information that the Underwriters have furnished to the
  expressly for use in the Registration Statement, any preliminary prospectus or
  the Prospectus (or any amendment or supplement thereto) are the statements set
  forth (A) as the paragraph on the inside front cover page of the Prospectus
  concerning stabilization by the Underwriters and (B) in the table in the first
  paragraph and as the second, fourth and eighth paragraphs under the caption
  "Underwriting" in the Prospectus; and the Underwriters confirm that such
  statements are correct. The indemnity agreement set forth in this Section 8(b)
  shall be in addition to any liabilities that each Underwriter may otherwise
  have.

        (c) Notifications and Other Indemnification Procedures.  Promptly after
  receipt by an indemnified party under this Section 8 of notice of the
  commencement of any action, such indemnified party will, if a claim in respect
  thereof is to be made against an indemnifying party under this Section 8,
  notify the indemnifying party in writing of the commencement thereof, but the
  omission so to notify the indemnifying party will not relieve it from any
  liability which it may have to any indemnified party for contribution or
  otherwise than under the indemnity agreement contained in this Section 8 or to
  the extent it is not prejudiced as a proximate result of such failure.  In
  case any such action is brought against any indemnified party and such
  indemnified party seeks or intends to seek indemnity from an indemnifying

                                      19

 
  party, the indemnifying party will be entitled to participate in, and, to the
  extent that it shall elect, jointly with all other indemnifying parties
  similarly notified, by written notice delivered to the indemnified party
  promptly after receiving the aforesaid notice from such indemnified party, to
  assume the defense thereof with counsel reasonably satisfactory to such
  indemnified party; provided, however, if the defendants in any such action
  include both the indemnified party and the indemnifying party and the
  indemnified party shall have reasonably concluded that a conflict may arise
  between the positions of the indemnifying party and the indemnified party in
  conducting the defense of any such action or that there may be legal defenses
  available to it and/or other indemnified parties which are different from or
  additional to those available to the indemnifying party, the indemnified party
  or parties shall have the right to select separate counsel to assume such
  legal defenses and to otherwise participate in the defense of such action on
  behalf of such indemnified party or parties.  Upon receipt of notice from the
  indemnifying party to such indemnified party of such indemnifying party's
  election so to assume the defense of such action and approval by the
  indemnified party of counsel, the indemnifying party will not be liable to
  such indemnified party under this Section8 for any legal or other expenses
  subsequently incurred by such indemnified party in connection with the defense
  thereof unless (i) the indemnified party shall have employed separate counsel
  in accordance with the proviso to the next preceding sentence (it being
  understood, however, that the indemnifying party shall not be liable for the
  expenses of more than one separate counsel (together with local counsel),
  approved by the indemnifying party (Montgomery Securities in the case of
  Section 8(b) and Section 9), representing the indemnified parties who are
  parties to such action) or (ii) the indemnifying party shall not have employed
  counsel satisfactory to the indemnified party to represent the indemnified
  party within a reasonable time after notice of commencement of the action, in
  each of which cases the reasonable fees and expenses of counsel shall be at
  the expense of the indemnifying party.

       (d) Settlements.  The indemnifying party under this Section 8 shall not
 be liable for any settlement of any proceeding effected without its written
 consent, but if settled with such consent or if there be a final judgment for
 the plaintiff, the indemnifying party agrees to indemnify the indemnified party
 against any loss, claim, damage, liability or expense by reason of such
 settlement or judgment.  Notwithstanding the foregoing sentence, if at any time
 an indemnified party shall have requested an indemnifying party to reimburse
 the indemnified party for the reasonable fees and expenses of counsel as
 contemplated by Section 8(a) and Section 8(c) hereof, 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
 90 days after receipt by such indemnifying party of the aforesaid request and
 (ii) such indemnifying party shall not have reimbursed the indemnified party in
 accordance with such request prior to the date of such settlement.  No
 indemnifying party shall, without the prior written consent of the indemnified
 party, effect any settlement, compromise or consent to the entry of judgment in
 any pending or threatened action, suit or proceeding in respect of which any
 indemnified party is or could have been a party and indemnity was or could have
 been sought hereunder by such indemnified party, unless such settlement,
 compromise or consent includes an unconditional release of such indemnified
 party from all liability on claims that are the subject matter of such action,
 suit or proceeding.

                                      20

 
          SECTION 9.  CONTRIBUTION.

          If the indemnification provided for in Section 8 is for any reason
held to be unavailable to or otherwise insufficient to hold harmless an
indemnified party in respect of any losses, claims, damages, liabilities or
expenses referred to therein, then each indemnifying party shall contribute to
the aggregate amount paid or payable by such indemnified party, as incurred, as
a result of any losses, claims, damages, liabilities or expenses referred to
therein (i) in such proportion as is appropriate to reflect the relative
benefits received by the Company, on the one hand, and the Underwriters, on the
other hand, from the offering of the Common Shares pursuant to this Agreement 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 the Underwriters, on the other hand, in
connection with the statements or omissions or inaccuracies in the
representations and warranties herein which resulted in such losses, claims,
damages, liabilities or expenses, as well as any other relevant equitable
considerations.  The relative benefits received by the Company, on the one hand,
and the Underwriters, on the other hand, in connection with the offering of the
Common Shares pursuant to this Agreement shall be deemed to be in the same
respective proportions as the total net proceeds from the offering of the Common
Shares pursuant to this Agreement (before deducting expenses) received by the
Company, and the total underwriting discount received by the Underwriters, in
each case as set forth on the front cover page of the Prospectus (or, if
Rule 434 under the Securities Act is used, the corresponding location on the
Term Sheet) bear to the aggregate initial public offering price of the Common
Shares as set forth on such cover.  The relative fault of the Company, on the
one hand, and the Underwriters, on the other hand, shall be determined by
reference to, among other things, whether any such untrue or alleged untrue
statement of a material fact or omission or alleged omission to state a material
fact or any such inaccurate or alleged inaccurate representation or warranty
relates to information supplied by the Company, on the one hand, or the
Underwriters, on the other hand, 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,
claims, damages, liabilities and expenses referred to above shall be deemed to
include, subject to the limitations set forth in Section 8(c), any legal or
other fees or expenses reasonably incurred by such party in connection with
investigating or defending any action or claim.  The provisions set forth in
Section 8(c) with respect to notice of commencement of any action shall apply if
a claim for contribution is to be made under this Section 9; provided, however,
that no additional notice shall be required with respect to any action for which
notice has been given under Section 8(c) for purposes of indemnification.

          The Company and the Underwriters agree that it would not be just and
equitable if contribution pursuant to this Section 9 were determined by pro rata
allocation (even if the Underwriters were treated as one entity for such
purpose) or by any other method of allocation which does not take account of the
equitable considerations referred to in this Section 9.

          Notwithstanding the provisions of this Section 9, no Underwriter shall
be required to contribute any amount in excess of the underwriting commissions
received by such Underwriter in connection with the Common Shares underwritten
by it and distributed to the public.  No person guilty of fraudulent
misrepresentation (within the meaning of Section 11(f) of the Securities Act)
shall be entitled to contribution from any person who was not guilty of such

                                      21

 
fraudulent misrepresentation.  The Underwriters' obligations to contribute
pursuant to this Section 9 are several, and not joint, in proportion to their
respective underwriting commitments as set forth opposite their names in
Schedule A.  For purposes of this Section 9, each officer and employee of an
- ----------                                                                  
Underwriter and each person, if any, who controls an Underwriter within the
meaning of the Securities Act and the Exchange Act shall have the same rights to
contribution as such Underwriter, and each director of the Company, each officer
of the Company who signed the Registration Statement, and each person, if any,
who controls the Company with the meaning of the Securities Act and the Exchange
Act shall have the same rights to contribution as the Company.

          SECTION 10. DEFAULT OF ONE OR MORE OF THE SEVERAL UNDERWRITERS.  If,
on the First Closing Date or the Second Closing Date, as the case may be, any
one or more of the several Underwriters shall fail or refuse to purchase Common
Shares that it or they have agreed to purchase hereunder on such date, and the
aggregate number of Common Shares which such defaulting Underwriter or
Underwriters agreed but failed or refused to purchase does not exceed 10% of the
aggregate number of the Common Shares to be purchased on such date, the other
Underwriters shall be obligated, severally, in the proportions that the number
of Firm Common Shares set forth opposite their respective names on Schedule A
                                                                   ----------
bears to the aggregate number of Firm Common Shares set forth opposite the names
of all such non-defaulting Underwriters, or in such other proportions as may be
specified by the Representatives with the consent of the non-defaulting
Underwriters, to purchase the Common Shares which such defaulting Underwriter or
Underwriters agreed but failed or refused to purchase on such date. If, on the
First Closing Date or the Second Closing Date, as the case may be, any one or
more of the Underwriters shall fail or refuse to purchase Common Shares and the
aggregate number of Common Shares with respect to which such default occurs
exceeds 10% of the aggregate number of Common Shares to be purchased on such
date, and arrangements satisfactory to the Representatives and the Company for
the purchase of such Common Shares are not made within 48 hours after such
default, this Agreement shall terminate without liability of any party to any
other party except that the provisions of Section 4, Section 8 and Section 9
shall at all times be effective and shall survive such termination.  In any such
case either the Representatives or the Company shall have the right to postpone
the First Closing Date or the Second Closing Date, as the case may be, but in no
event for longer than seven days in order that the required changes, if any, to
the Registration Statement and the Prospectus or any other documents or
arrangements may be effected.

          As used in this Agreement, the term "Underwriter" shall be deemed to
include any person substituted for a defaulting Underwriter under this
Section 10.  Any action taken under this Section 10 shall not relieve any
defaulting Underwriter from liability in respect of any default of such
Underwriter under this Agreement.

          SECTION 11. TERMINATION OF THIS AGREEMENT.  Prior to the First Closing
Date this Agreement maybe terminated by the Representatives by notice given to
the Company if at any time (i) trading or quotation in any of the Company's
securities shall have been suspended or limited by the Commission or by the
Nasdaq Stock Market, or trading in securities generally on either the Nasdaq
Stock Market or the New York Stock Exchange shall have been suspended or
limited, or minimum or maximum prices shall have been generally established on
any of such stock exchanges by the Commission or the NASD; (ii) a general
banking moratorium shall have been declared by any of federal, New York ,
Delaware or California authorities; (iii) there shall have occurred any outbreak
or escalation of national or international hostilities or any crisis or

                                      22

 
calamity, or any change in the United States or international financial markets,
or any substantial change or development involving a prospective substantial
change in United States' or international political, financial or economic
conditions, as in the judgment of the Representatives is material and adverse
and makes it impracticable to market the Common Shares in the manner and on the
terms described in the Prospectus or to enforce contracts for the sale of
securities; (iv) in the judgment of the Representatives there shall have
occurred any Material Adverse Change; or (v) the Company shall have sustained a
loss by strike, fire, flood, earthquake, accident or other calamity of such
character as in the judgment of the Representatives may interfere materially
with the conduct of the business and operations of the Company regardless of
whether or not such loss shall have been insured.  Any termination pursuant to
this Section 11 shall be without liability on the part of (a) the Company to any
Underwriter, except that the Company shall be obligated to reimburse the
expenses of the Representatives and the Underwriters pursuant to Sections 4
and 6 hereof, (b) any Underwriter to the Company, or (c) of any party hereto to
any other party except that the provisions of Section 8 and Section 9 shall at
all times be effective and shall survive such termination.

          SECTION 12. REPRESENTATIONS AND INDEMNITIES TO SURVIVE DELIVERY.  The
respective indemnities, agreements, representations, warranties and other
statements of the Company, of its officers and of the several Underwriters set
forth in or made pursuant to this Agreement will remain in full force and
effect, regardless of any investigation made by or on behalf of any Underwriter
or the Company or any of its or their partners, officers or directors or any
controlling person, as the case may be, and will survive delivery of and payment
for the Common Shares sold hereunder and any termination of this Agreement.

          SECTION 13. NOTICES.    All communications hereunder shall be in
writing and shall be mailed, hand delivered or telecopied and confirmed to the
parties hereto as follows:

If to the Representatives:

     Montgomery Securities
     600 Montgomery Street
     San Francisco, California  94111
     Facsimile:  415-249-5558
     Attention:  Richard A. Smith

 with a copy to:

     Montgomery Securities
     600 Montgomery Street
     San Francisco, California  94111
     Facsimile:  (415) 249-5553
     Attention:  David A. Baylor, Esq.

                                      23

 
If to the Company:

     Megabios Corp.
     863 A Mitten Road
     Burlingame, California  94010
     Facsimile:  (650) 652-1990
     Attention:  Patrick G. Enright

Any party hereto may change the address for receipt of communications by giving
written notice to the others.

          SECTION 14.  SUCCESSORS.    This Agreement will inure to the benefit
of and be binding upon the parties hereto, including any substitute Underwriters
pursuant to Section 10 hereof, and to the benefit of the employees, officers and
directors and controlling persons referred to in Section 8 and Section 9, and in
each case their respective successors, and no other person will have any right
or obligation hereunder.  The term "successors" shall not include any purchaser
of the Common Shares as such from any of the Underwriters merely by reason of
such purchase.

          SECTION 15.  PARTIAL UNENFORCEABILITY.  The invalidity or
unenforceability of any Section, paragraph or provision of this Agreement shall
not affect the validity or enforceability of any other Section, paragraph or
provision hereof.  If any Section, paragraph or provision of this Agreement is
for any reason determined to be invalid or unenforceable, there shall be deemed
to be made such minor changes (and only such minor changes) as are necessary to
make it valid and enforceable.

          SECTION 16.  GOVERNING LAW PROVISIONS.  THIS AGREEMENT SHALL BE
GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE INTERNAL LAWS OF THE STATE OF
CALIFORNIA APPLICABLE TO AGREEMENTS MADE AND TO BE PERFORMED IN SUCH STATE.

          Consent to Jurisdiction. Any legal suit, action or proceeding arising
out of or based upon this Agreement or the transactions contemplated hereby
("Related Proceedings") may be instituted in the federal courts of the United
States of America located in the City and County of San Francisco or the courts
of the State of California in each case located in the City and County of San
Francisco (collectively, the "Specified Courts"), and each party irrevocably
submits to the exclusive jurisdiction (except for proceedings instituted in
regard to the enforcement of a judgment of any such court (a "Related
Judgment"), as to which such jurisdiction is non-exclusive) of such courts in
any such suit, action or proceeding.  Service of any process, summons, notice or
document by mail to such party's address set forth above shall be effective
service of process for any suit, action or other proceeding brought in any such
court.  The parties irrevocably and unconditionally waive any objection to the
laying of venue of any suit, action or other proceeding in the Specified Courts
and irrevocably and unconditionally waive and agree not to plead or claim in any
such court that any such suit, action or other proceeding brought in any such
court has been brought in an inconvenient forum.

                                      24

 
          SECTION 17.  GENERAL PROVISIONS.  This Agreement constitutes the
entire agreement of the parties to this Agreement and supersedes all prior
written or oral and all contemporaneous oral agreements, understandings and
negotiations with respect to the subject matter hereof.  This Agreement may be
executed in two or more counterparts, each one of which shall be an original,
with the same effect as if the signatures thereto and hereto were upon the same
instrument.  This Agreement may not be amended or modified unless in writing by
all of the parties hereto, and no condition herein (express or implied) may be
waived unless waived in writing by each party whom the condition is meant to
benefit.  The Table of Contents and the Section headings herein are for the
convenience of the parties only and shall not affect the construction or
interpretation of this Agreement.

          Each of the parties hereto acknowledges that it is a sophisticated
business person who was adequately represented by counsel during negotiations
regarding the provisions hereof, including, without limitation, the
indemnification provisions of Section 8 and the contribution provisions of
Section 9, and is fully informed regarding said provisions.  Each of the parties
hereto further acknowledges that the provisions of Sections 8 and 9 hereto
fairly allocate the risks in light of the ability of the parties to investigate
the Company, its affairs and its business in order to assure that adequate
disclosure has been made in the Registration Statement, any preliminary
prospectus and the Prospectus (and any amendments and supplements thereto), as
required by the Securities Act and the Exchange Act.

                                      25

 
     If the foregoing is in accordance with your understanding of our agreement,
kindly sign and return to the Company the enclosed copies hereof, whereupon this
instrument, along with all counterparts hereof, shall become a binding agreement
in accordance with its terms.

                              Very truly yours,

                              MEGABIOS CORP.



                               By:__________________________
                                         [Title]


     The foregoing Underwriting Agreement is hereby confirmed and accepted by
the Representatives in San Francisco, California as of the date first above
written.

MONTGOMERY SECURITIES
HAMBRECHT & QUIST LLC
Acting as Representatives of the
several Underwriters named in
the attached Schedule A.

By MONTGOMERY SECURITIES



By:_____________________________

                                      26

 
                                   SCHEDULE A



                               NUMBER OF
UNDERWRITERS               FIRM COMMON SHARES
                            TO BE PURCHASED

Montgomery Securities......      [___]
Hambrecht & Quist LLC......      [___]
[___]......................      [___]
[___]......................      [___]
 
     Total.................     2,500,000