<PAGE>
                                                                     Exhibit 3.9

                          AMENDED AND RESTATED BYLAWS
                                      OF
                          WESTERN GAS RESOURCES, INC.
                     - - - - - - - - - - - - - - - - - - -

                                  ARTICLE I.

                                    OFFICES
                                    -------

          Section 1.   The registered office of the corporation shall be in the
City of Wilmington, County of New Castle, State of Delaware.

          Section 2.  The corporation may also have offices at such other
places, both within and without the State of Delaware, as the Board of Directors
may from time to time determine or the business of the corporation may require.


                                  ARTICLE II.

                           MEETINGS OF STOCKHOLDERS
                           ------------------------

          Section 1. All meetings of the stockholders for the election of
directors shall be held at such place either within or without the State of
Delaware as shall be designated from time to time by the Board of Directors and
stated in the notice of the meeting. Meetings of stockholders for any other
purpose may be held at such time and place, within or without the State of
Delaware, as shall be stated in the notice of the meeting or in a duly executed
waiver of notice thereof.

          Section 2.  (a)  Annual meetings of stockholders, commencing with the
year 1990, shall be held on the second Wednesday in May, if not a legal holiday,
and if a legal holiday, then on the next secular day following, at ten o'clock
a.m., or at such other date and time as shall be designated from time to time by
the Board of Directors and stated in the notice of the meeting, at which they
shall elect a class of  Directors and transact such other business as may
properly be brought before the meeting.

          (b)  At each meeting of stockholders, the Chairman of the Board, or,
in the absence of the Chairman of the Board, the President, shall act as
chairman.  The order of business at each such meeting shall be as determined by
the chairman of the meeting.  The chairman of the meeting shall have the right
and authority to prescribe such rules,  regulations  and procedures and to do
all such acts and things as are necessary or desirable for the proper conduct of
the meeting, including, without limitation, the establishment of procedures for
the maintenance of order and safety, limitations on the time  allotted to
questions or comments on the affairs of the   corporation, restrictions on entry
to such meeting after the time prescribed for the commencement thereof, and the
opening and closing of the voting polls.  The chairman of the meeting shall
announce at each such meeting the date and time of the opening and closing of
the voting polls for each matter upon which the stockholders will vote at such
meeting.

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          (c) In order for business to be properly brought before the meeting by
a stockholder, the business must be legally proper and written notice thereof
must have been filed with the Secretary of the corporation not less than 60 nor
more than 120 days prior to the meeting.  Each such notice shall set forth: (i)
the name and address of the stockholder who intends to make the proposal as the
same appear in the corporation's records; (ii) the class and number of shares of
stock of the corporation that are beneficially owned, directly or indirectly, by
such stockholder, and if such stockholder is not the record holder of such
shares, the name, based upon the best knowledge of such stockholder, of the
record holder thereof; and (iii) a clear and concise statement of the proposal
and the stockholder's reasons for supporting it.  The filing of a stockholder
notice as required above shall not, in and of itself, constitute the making of
the proposal described therein.  If the chairman of the meeting determines that
any proposed business has not been properly brought before the meeting, he shall
declare such business out of order; and such business shall not be conducted at
the meeting.

          (d) Either the Board of Directors or, in the absence of an appointment
of inspectors by the Board, the Chairman of the Board or the President shall, in
advance of each meeting of the stockholders, appoint one or more inspectors to
act at such meeting and make a written report thereof.  In connection with any
such appointment, one or more persons may, in the discretion of the body or
person making such appointment, be designated as alternate inspectors to replace
any inspector who fails to act.   If  no inspector or alternate is able to act
at  any meeting of stockholders, the chairman of  such meeting shall appoint one
or more inspectors to act at such meeting.  Each such inspector shall perform
such duties as are required by law and as shall be specified by the Board, the
chairman of the board, the president or the chairman of the meeting.  Each such
inspector, before entering upon the discharge of his duties, shall take and sign
an oath faithfully to execute the duties of inspector with strict impartiality
and according to the best of his ability.  Inspectors need not be stockholders.
No director or nominee for the office or director shall be appointed such an
inspector.

          Section 3.  Written notice of the annual meeting stating the place,
date and hour of the meeting shall be given to each stockholder entitled to vote
at such meeting not less than ten nor more than sixty days before the date of
the meeting.

          Section 4.  The officer who has charge of the stock ledger of the
corporation shall prepare and make, at least ten days before each annual meeting
of stockholders, a complete list of the stockholders entitled to vote at the
meeting, arranged in alphabetical order, and showing the address of each
stockholder and the number of shares registered in the name of each stockholder.
Such list shall be open to the examination of any stockholder, for any purpose
germane to the meeting, during ordinary business hours, for a period of at least
ten days prior to the meeting, either at a place within the city where the
meeting is to be held, which place shall be specified in the notice of the
meeting, or, if not so specified, at the place where the meeting is to be held.
The list shall also be produced and kept at the time and place of the meeting
during the whole time thereof, and may be inspected by any stockholder who is
present.

          Section 5.  Special meetings of the stockholders, for any purpose or
purposes, unless otherwise prescribed by statute or by the certificate of
incorporation, may be called by the president and shall be called by the
president or secretary at the request in writing of sixty percent of the
directors, or at the request in writing of stockholders owning twenty-five
percent of the entire capital stock of the corporation issued and outstanding
and entitled to vote. Such

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request shall state the purpose or purposes of the proposed meeting.

          Section 6.  Written notice of a special meeting stating the place,
date and hour of the meeting and the purpose or purposes for which the meeting
is called, shall be given not less than ten nor more than sixty days before the
date of the meeting, to each stockholder entitled to vote at such meeting.

          Section 7.  Business transacted at any special meeting of stockholders
shall be limited to the purposes stated in the notice.
          
          Section 8. The holders of a majority of the stock issued and
outstanding and entitled to vote thereat, present in person or represented by
proxy, shall constitute a quorum at all meetings of the stockholders for the
transaction of business except as otherwise provided by statute or by the
certificate of incorporation. If, however, such quorum shall not be present or
represented at any meeting of the stockholders, the stockholders entitled to
vote thereat, present in person or represented by proxy, shall have power to
adjourn the meeting from time to time, without notice other than announcement at
the meeting, until a quorum shall be present or represented. At such adjourned
meeting, at which a quorum shall be present or represented, any business may be
transacted which might have been transacted at the meeting as originally
notified. If the adjournment is for more than thirty days, or if after the
adjournment a new record date is fixed for the adjourned meeting, a notice of
the adjourned meeting shall be given to each stockholder of record entitled to
vote at the meeting.

          Section 9. When a quorum is present at any meeting, the vote of the
holders of a majority of the stock having voting power present in person or
represented by proxy shall decide any question (other than the election of
directors) brought before such meeting, unless the question is one upon which by
express provision of the statutes or of the certificate of incorporation a
different vote is required, in which case such express provision shall govern
and control the decision of such question. Directors shall be elected by
plurality vote.

          Section 10. Each stockholder shall at every meeting of the
stockholders be entitled to one vote in person or by proxy for each share of the
capital stock having voting power held by such stockholder, but no proxy shall
be voted on after three years from its date, unless the proxy provides for a
longer period.


                                 ARTICLE III.

                                  DIRECTORS
                                  ---------

          Section 1.  The business and affairs of the corporation shall be
managed by or under the direction of the Board of Directors, which may exercise
all such powers of the corporation and do all such lawful acts and things as are
not by law or by the certificate of incorporation or these bylaws directed or
required to be exercised or done by the stockholders.

          Section 2.  Except as otherwise provided in any resolution or
resolutions adopted by the Board of Directors pursuant to the provisions of
Article IV of the certificate of incorporation

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relating to the rights of holders of any class or series of stock having a
preference over the common stock as to dividends or upon liquidation, the number
of directors of the corporation shall be eight (8); that the additional member
of the Board of Directors resulting from such amendment shall be a Class Two
director; and that the vacancy thus created shall be filled by vote of the
stockholders at the annual meeting of stockholders to be held on May 1, 1991,
but the

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number thereof may be increased without limit or decreased to not less than
three (two of whom shall not be officers or employees of the corporation) by
amendment to this Section 2.

          Section 3. Vacancies and newly created directorships resulting from
any increase in the authorized number of directors may be filled by the
directors then in office, or by a sole remaining director, and the directors so
chosen shall hold office until the expiration of the terms of the directorships
whose vacancy is being filled and until their successors are duly elected and
qualified, unless sooner displaced. If there are no directors in office, then an
election of directors may be held in the manner provided by statute.

          Section 4. Subject to the rights of the holders of any class or series
of stock having a preference over the Common Stock as to dividends or upon
liquidation, nominations for the election of directors may be made by the Board
of Directors or by any stockholder entitled to vote for the election of
directors. Any stockholder entitled to vote for the election of directors at a
meeting may nominate persons for election as directors only if written notice of
such stockholder's intent to make such nomination is given, either by personal
delivery or by postage prepaid, certified United States mail, return receipt
requested, to the secretary of the corporation not later than (i) with respect
to an election to be held at an annual meeting of stockholders, ninety days in
advance of such meeting and (ii) with respect to an election to be held at a
special meeting of stockholders for the election of directors, the close of
business on the seventh day following the date on which notice of such meeting
is first given to stockholders. Each such notice shall set forth: (a) the name
and address of the stockholder who intends to make the nomination of the person
or persons to be nominated; (b) a representation that the stockholder is a
holder of record of stock of the corporation entitled to vote at such meeting
and intends to appear in person or by proxy at the meeting to nominate the
person or persons specified in the notice; (c) a description of all arrangements
or understandings between the stockholder and each nominee and any other person
or entity (naming such person or entity) pursuant to which the nomination or
nominations are to be made by the stockholder; (d) such other information
regarding each nominee proposed by such stockholder as would have been required
to be included in a proxy statement filed pursuant to the Securities Exchange
Act of 1934, as amended, and the rules and regulations promulgated by the
Securities and Exchange commission thereunder, had each nominee been nominated,
or intended to be nominated, for election as a director by the Board of
Directors; and (e) the consent of each nominee to serve as a director of the
corporation if so elected. The chairman of the meeting may refuse to acknowledge
and place upon the ballot the nomination of any person not made in strict
compliance with the foregoing procedure.

          Section 5. The Board of Directors may adopt and from time to time
amend and repeal such rules and regulations not inconsistent with the applicable
provisions of law, the certificate of incorporation or these bylaws for the
conduct of its meetings and the management of the affairs of the corporation as
the Board may deem proper.

                      MEETINGS OF THE BOARD OF DIRECTORS
                      ----------------------------------

          Section 6.  The Board of Directors of the corporation may hold
meetings, both regular and special, either within or without the State of
Delaware.

          Section 7.  An annual meeting of the Board of Directors shall be held
immediately

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following and at the same place as the annual meeting of stockholders and no
notice of such meeting shall be necessary to the newly elected directors in
order legally to constitute the meeting, provided a quorum shall be present. In
the event such meeting is not held at such time and place, the meeting may be
held at such time and place as shall be specified in a notice given as
hereinafter provided for special meetings of the Board of Directors, or as shall
be specified in a written waiver signed by all of the directors.

          Section 8.  Regular meetings of the Board of Directors may be held
without notice at such time and at such place as shall from time to time be
determined by the Board.

          Section 9. Special meetings of the Board of Directors may be called by
the chairman of the board or the president on two days' notice to each director,
either personally or by mail or telegram; special meetings shall be called by
the president or secretary in like manner and on like notice on the written
request of two directors.

          Section 10. At all meetings of the Board of Directors the presence of
sixty percent of the directors shall constitute a quorum for the transaction of
business and only the act of sixty percent of all of the directors then in
office shall be the act of the Board of Directors, except as may be otherwise
specifically provided by statute, by the certificate of incorporation, by any
resolution adopted by the Board of Directors in accordance with Article IV of
the certificate of incorporation or by these bylaws. If a quorum shall not be
present at any meeting of the Board of Directors, the directors present thereat
may adjourn the meeting from time to time, without notice other than
announcement at the meeting, until a quorum shall be present.

          Section 11.  Unless otherwise restricted by the certificate of
incorporation or these bylaws, any action required or permitted to be taken at
any meeting of the Board of Directors or of any committee thereof may be taken
without a meeting, if sixty percent of the members of the Board or a majority of
the members of the committee, as the case may be, consent thereto in writing,
the writing is filed with the minutes of proceedings of the Board or committee,
and prompt notice of the action so taken is given to each director who did not
consent thereto in writing.

          Section 12. The members of the Board of Directors or any committee
thereof may participate in a meeting of the Board or committee utilizing
conference telephone or similar communications equipment by means of which all
persons participating in the meeting can hear each other and such participation
shall constitute presence in person at such meeting.

                            COMMITTEES OF DIRECTORS
                            -----------------------

          Section 13.   There shall be an Executive Committee of  the Board of
Directors of the Corporation consisting of at least two (2) but not more than
four (4) members of the Board of Directors, elected to such committee by the
Board on an annual basis.  The Executive Committee shall have and may exercise,
between meetings of the Board of Directors, all the power and authority of the
board in the management of the business affairs of the corporation; provided,
however, that the Executive Committee shall not have the power or authority to
do any of the following:

             (a)  amend the certificate of incorporation of the corporation;

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<PAGE>
 
             (b) adopt an agreement of merger or consolidation involving the
                 corporation;

             (c) recommend to the stockholders the sale, lease or exchange of
                 all or substantially all of the property and assets of the
                 corporation;

             (d) recommend to the stockholders a dissolution of the corporation
                 or a revocation of a dissolution;

             (e) adopt, amend or repeal any bylaw;

             (f) fill vacancies on the Board of Directors or on any committee
                 of the Board, including the Executive Committee;

             (g) amend or repeal any resolution of the Board of Directors;

             (h) declare a dividend; or

             (i) authorize the issuance of stock of the corporation.

          Section 14. The Executive Committee shall, subject to the provisions
of law and any other provisions of these bylaws, have full authority and power
to cause the corporation to do the following:

             (a) To deal in real and personal property of the corporation; to
                 create and/or contribute property of the corporation to any
                 entity or business organization formed by the corporation,
                 either alone or with third parties; to pay rom the
                 corporation's funds any and all expenses and fees; to obtain
                 and maintain insurance coverage concerning the property of the
                 corporation.

             (b) To execute and deliver on behalf of the corporation all leases,
                 bills of sales, assignments, deeds, unitization agreements,
                 contracts, farm-outs and other instruments of transfer; all
                 checks, drafts and other orders for the payment of corporation
                 funds; all contracts or instruments concerning the acquisition,
                 construction, management, operation or disposition of corporate
                 assets; all bonds, promissory notes, mortgages, deeds of trust,
                 security agreements and other similar documents; and all other
                 instruments, documents, contracts or agreements of any kind or
                 character relating to the affairs of the corporation; and to
                 delegate in writing to the officers of the corporation the
                 authority to sign such instruments, notes, deeds, contracts,
                 agreements and documents.

             (c) To exercise all rights, powers and authority as is necessary or
                 prudent in the operation and maintenance of the business of the
                 corporation.

             (d) To directly, or by delegation of authority to the officers of
                 the corporation, appoint, employ, remove, suspend and discharge
                 any of the following:

                 (1) Managers, assistants, independent contractors, geologists,

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                   geophysicists, land men, employees and agents as from time to
                   time may be deemed advisable and to determine the duties and
                   fix and change the salaries and other terms of employment of
                   such persons.

                                       8
<PAGE>
 
               (2) Qualified technical personnel temporarily employed or to be
                   employed on specific problems incident to the operation of
                   the corporation and its businesses.

               (3) Attorneys, architects, engineers, accountants, contractors,
                   consultants, advertising agencies, sales representatives and
                   all such other agents or independent contractors as such
                   officers shall deem necessary or advisable for the
                   furtherance of the corporation's purposes and operations.

          Notwithstanding the above, in no event shall the Executive Committee
have the authority to approve: (i) with respect to gas purchase and sale
agreements, any agreement that provides for the sale or purchase in any single
year of gas in excess of Thirty-Five Million Dollars ($35,000,000); (ii) with
respect to the purchase of operating supplies, capital expenditures or general
and administrative expenditures, any single expenditure or group of related
expenditures in excess of Ten Million Dollars ($10,000,000); or (iii) any
business transaction with an affiliate of the corporation, without the approval
of the Board of Directors. The term "affiliate" as used herein shall mean a
person or entity, of any kind or nature, controlling, controlled by or under
common control with the corporation and shall include, without limitation, any
subsidiaries of the corporation and any person or entity owning, directly or
indirectly, five percent or more of the capital stock of the corporation.

          Section 15. There shall be an Audit Committee of the Board of
Directors of the corporation consisting of at least two members of the Board of
Directors elected to such committee by the board on an annual basis. The initial
members of the Audit Committee shall be the two directors named in the
certificate of incorporation who are not officers or employees of the
corporation or of any party to a subscription agreement with the corporation.
The members of the audit committee elected hereafter shall be eligible to serve
thereon under the rules of the New York Stock Exchange as in effect from time to
time.

          Section 16. The Board of Directors may designate one or more
additional committees, each committee to consist of two or more directors of the
corporation. The Board may designate one or more directors as alternate members
of any committee, who may replace any absent or disqualified member at any
meeting of the committee. Any such committee, to the extent provided in the
resolution, shall have and may exercise the powers of the Board of Directors in
the management of the business and affairs of the corporation, and may authorize
the seal of the corporation to be affixed to all papers which may require it.
Such committee or committees shall have such name or names as may be determined
from time to time by resolution adopted by the Board of Directors.

          Section 17.   Regular meetings of the Executive Committee or any other
committee of the Board of Directors, of which no notice shall be necessary, may
be held at such times and places as shall be fixed by resolution adopted by a
majority of the members thereof.  Special meetings of the Executive Committee or
any other committee of the Board shall be called at the request of any member
thereof.  Any special meeting of the Executive Committee or any other committee
of the Board shall be a legal meeting, without any notice thereof having been
given,

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<PAGE>
 
if all of the members thereof shall be present or if notice thereof shall have
been given to each member on the day prior to the day on which the meeting is to
be held. The Executive Committee or any other committee may adopt such rules and
regulations not inconsistent with the provisions of law, the certificate of
incorporation or these bylaws for the conduct of its meetings as such committee
may deem proper. The majority of the Executive Committee or any other committee
of the Board shall constitute a quorum for the transaction of business at any
meeting, and the vote of the majority of the members thereof present at any
meeting at which a quorum is present shall be the act of such committee. The
Executive Committee or any other committee of the Board of Directors shall keep
written minutes of its proceedings and shall report on such proceedings to the
Board.

                           COMPENSATION OF DIRECTORS
                           -------------------------

          Section 18. The Board of Directors shall have the authority to adopt
resolutions fixing the compensation to be paid to directors for service as a
director of the corporation. The directors may be paid their expenses, if any,
of attendance at each meeting of the Board of Directors and may be paid a fixed
sum for attendance at each meeting of the Board of Directors or a stated salary
as a director. No such payment shall preclude any director from serving the
corporation in any other capacity and receiving compensation therefor. Members
of special or standing committees may be allowed like compensation for attending
committee meetings.


                                  ARTICLE IV.

                                    NOTICES
                                    -------

          Section 1. Whenever, under statutory provisions or pursuant to the
certificate of incorporation or these bylaws, notice is required to be given to
any director or stockholder, it shall not be construed to require personal
notice, but such notice may be given in writing, by mail, addressed to such
director or stockholder, at his address as it appears on the records of the
corporation, with postage thereon prepaid, and such notice shall be deemed to be
given at the time when the same shall be deposited in the United States mail.
Notice to directors may also be given by prepaid telegram.

          Section 2.  Whenever any notice is required to be given under
statutory provisions or pursuant to the certificate of incorporation or these
bylaws, a waiver thereof in writing, signed by the person or persons entitled to
said notice, whether before or after the time stated therein, shall be deemed
equivalent thereto.


                                  ARTICLE V.

                                   OFFICERS
                                   --------

          Section 1. The officers of the corporation shall be chosen by the
Board of Directors and shall consist of: (i) a chairman of the board and chief
executive officer (who shall be a member of the Board of Directors); (ii) a
president and chief operating officer; (iii) one or more vice presidents; (iv) a
secretary; (v) a treasurer; and (vi) such other officers, with such duties, as
the

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 Board of Directors shall direct.

          Section 2.  The Board of Directors, at its first meeting after each
annual meeting of stockholders, shall elect or appoint the officers of the
corporation. The Board of Directors, the

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chairman of the board or the president at any time may also appoint one or more
assistant secretaries and assistant treasurers.

          Section 3.  The Board of Directors may appoint such other officers and
agents as it shall deem necessary, who shall hold their offices for such terms
and shall exercise such powers and perform such duties as shall be determined
from time to time by the Board of Directors.

          Section 4.  The salaries of the chairman of the board, of the
president, and of any senior vice president of the corporation shall be fixed by
the Board of Directors.

          Section 5.  Except as may be otherwise provided by the Board of
Directors or in these bylaws, each officer of the corporation shall hold office
until the first meeting of directors after the next annual meeting of
stockholders following his election or appointment and until his successor is
chosen and qualified. Any officer elected or appointed by the Board of Directors
may be removed at any time by the Board of Directors. If the office of any
officer becomes vacant for any reason, the vacancy shall be filled by the Board
of Directors.

                           THE CHAIRMAN OF THE BOARD
                           -------------------------

          Section 6. The chairman of the board and chief executive officer shall
be the chief executive officer of the corporation. Subject to the provisions of
these bylaws, the chairman of the board shall have general supervision of the
affairs of the corporation and shall have general and active control of all its
business. He shall see that all orders and resolutions of the Board of Directors
are carried into effect. He shall have the power and general authority to
exercise all the powers usually appertaining to the office of chief executive
officer of a corporation, except as otherwise provided by statute, the
certificate of incorporation or these bylaws. He shall report as to the
operations of the corporation to the Board of Directors and, with the president,
to the stockholders at or prior to each annual meeting of the stockholders, and
he shall from time to time report to the Board of Directors matters within his
knowledge which the interest of the corporation may require to be so reported.

                                 THE PRESIDENT
                                 -------------

          Section 7. The president and chief operating officer shall be the
chief operating officer of the corporation and, subject to the direction of the
Board of Directors and the chairman of the board, shall have and exercise direct
charge of and general supervision over the business affairs and employees of the
corporation. He shall also perform such other duties as may be prescribed by the
Board of Directors or the chairman of the board. In the event of the absence or
disability of the chairman of the board, the president shall preside when
present at meetings of the Board of Directors and of the stockholders and shall
perform the duties and exercise the powers of the chairman of the board. The
president shall have power and general authority to exercise all the powers
usually appertaining to the office of chief operating officer of a corporation,
except as otherwise provided by statute, the certificate of incorporation or
these bylaws.

                          THE SENIOR VICE PRESIDENT,
                          --------------------------

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                 VICE PRESIDENTS AND ASSISTANT VICE PRESIDENTS
                 ---------------------------------------------

          Section 8.  In the absence of the president or in the event of his
inability or refusal to act, the senior vice president (or in the event there be
more than one senior vice president, the senior vice presidents in the order
designated, or in the absence of any designation, then in the order of their
election) shall perform the duties of the president, and when so acting, shall
have all the powers of and be subject to all the restrictions upon the
president. The senior vice presidents shall perform such other duties and have
such other powers as the Board of Directors may from time to time prescribe.

          Section 9. The vice president or any assistant vice president, or if
there be more than one, the vice presidents and assistant vice presidents in the
order determined by the Board of Directors (or if there be no such
determination, then in the order of their election), shall in the absence of any
senior vice president or in the event of the inability or refusal to act of any
senior vice president, perform the duties and exercise the powers of such senior
vice president and shall perform such other duties and have such other powers as
the Board of Directors may from time to time prescribe.

                    THE SECRETARY AND ASSISTANT SECRETARIES
                    ---------------------------------------

          Section 10. The secretary shall attend all meetings of the Board of
Directors and all meetings of the stockholders and record all the proceedings of
the meetings of the stockholders and of the Board of Directors in a book to be
kept for that purpose and shall perform like duties for the standing committees
when required. He shall give, or cause to be given, notice of all meetings of
the stockholders and special meetings of the Board of Directors, and shall
perform such other duties as may be prescribed by the Board of Directors, the
president or the chairman of the board, under whose supervision he shall be. He
shall have custody of the corporate seal of the corporation and he, or an
assistant secretary, shall have authority to affix the same to any instrument
requiring it and when so affixed it may be attested by his signature or by the
signature of such assistant secretary. The Board of Directors may give general
authority to any other officer to affix the seal of the corporation and to
attest the affixing by his signature.

          Section 11. The assistant secretary, or if there be more than one, the
assistant secretaries in the order determined by the Board of Directors (or if
there be no such determination, then in the order of their election), shall, in
the absence of the secretary or in the event of his inability or refusal to act,
perform the duties and exercise the powers of the secretary and shall perform
such other duties and have such other powers as the Board of Directors may from
time to time prescribe.

                    THE TREASURER AND ASSISTANT TREASURERS
                    --------------------------------------

          Section 12. The treasurer shall have custody of the corporate funds
and securities of the corporation and shall keep full and accurate accounts of
receipts and disbursements in books belonging to the corporation and shall
deposit all moneys and other valuable effects in the name and to the credit of
the corporation in such depositories as may be designated by the Board of
Directors.

          Section 13.  The treasurer shall disburse the funds of the corporation
as may be ordered by the Board of Directors, taking proper vouchers for such
disbursements, and shall render to the

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president and the Board of Directors, at its regular meetings, or when the Board
of Directors so requires, an account of all his transactions as treasurer and of
the financial condition of the corporation.

          Section 14.  If required by the Board of Directors, the treasurer
shall give the corporation a bond (which shall be renewed every six years) in
such sum and with such surety or sureties as shall be satisfactory to the Board
of Directors for the faithful performance of the duties of his office and for
the restoration to the corporation, in case of his death, resignation,
retirement or removal from office, of all books, papers, vouchers, money and
other property of whatever kind in his possession or under his control belonging
to the corporation.

          Section 15. The assistant treasurer, or if there shall be more than
one, the assistant treasurers in the order determined by the Board of Directors
(or if there be no such determination, then in the order of their election),
shall, in the absence of the treasurer or in the event of his inability or
refusal to act, perform the duties and exercise the powers of the treasurer and
shall perform such other duties and have such other powers as the Board of
Directors may from time to time prescribe.


                                  ARTICLE VI.

                             CERTIFICATES OF STOCK
                             ---------------------

          Section 1. Every holder of stock in the corporation shall be entitled
to have a certificate, signed in the name of the corporation, by the chairman of
the board, the president or a vice president and the treasurer or an assistant
treasurer, or the secretary or an assistant secretary, certifying the number of
shares owned by him in the corporation.

          Section 2. Where a certificate is countersigned (1) by a transfer
agent other than the corporation or its employee, or (2) by a registrar other
than the corporation or its employee, any signature on the certificate may be
facsimile. In case any officer, transfer agent or registrar who has signed or
whose facsimile signature has been placed upon a certificate shall have ceased
to be such officer, transfer agent or registrar before such certificate is
issued, it may be issued by the corporation with the same effect as if he were
such officer, transfer agent or registrar at the date of issue.

                               LOST CERTIFICATES
                               -----------------

          Section 3. The Board of Directors may direct a new certificate or
certificates to be issued in place of any certificate or certificates
theretofore issued by the corporation alleged to have been lost, stolen or
destroyed, upon the making of an affidavit of that fact by the person claiming
the certificate of stock to be lost, stolen or destroyed. When authorizing such
issue of a new certificate or certificates, the Board of Directors may, in its
discretion and as a condition precedent to the issuance thereof, require the
owner of such lost, stolen or destroyed certificate or certificates, or his
legal representative, to advertise the same in such manner as it shall require
and/or to give the corporation a bond in such sum as it may direct as indemnity
against any claim that may be made against the corporation with respect to the
certificate alleged to have

                                      14
<PAGE>
 
been lost, stolen or destroyed.

                              TRANSFERS OF STOCK
                              ------------------

          Section 4. Upon surrender to the corporation or the transfer agent of
the corporation of a certificate for shares duly endorsed or accompanied by
proper evidence of succession, assignment or authority to transfer, it shall be
the duty of the corporation to issue a new certificate to the person entitled
thereto, cancel the old certificate and record the transaction upon its books.

                              FIXING RECORD DATE
                              ------------------

          Section 5. In order that the corporation may determine the
stockholders entitled to notice of and to vote at any meeting of stockholders or
any adjournment thereof, or to express consent to corporate action in writing
without a meeting, or entitled to receive payment of any dividend or other
distribution or allotment of any rights, or entitled to exercise any rights in
respect of any change, conversion or exchange of stock or for the purpose of any
other lawful action, the Board of Directors may fix, in advance, a record date,
which shall not be more than sixty nor less than ten days before the date of
such meeting, nor more than sixty days prior to any other action. A
determination of stockholders of record entitled to notice of and to vote at a
meeting of stockholders shall apply to any adjournment of the meeting; provided,
however, that the Board of Directors may fix a new record date for the adjourned
meeting.

                            REGISTERED STOCKHOLDERS
                            -----------------------

          Section 6. The corporation shall be entitled to recognize the
exclusive right of a person registered on its books as the owner of shares to
receive dividends, and to vote as such owner, and to hold liable for calls and
assessments a person registered on its books as the owner of shares, and shall
not be bound to recognize any equitable or other claim to or interest in such
share or shares on the part of any other person, whether or not it shall have
express or other notice thereof, except as otherwise provided by the laws of
Delaware.


                                 ARTICLE VII.

                              GENERAL PROVISIONS
                              ------------------
                   INDEMNIFICATION OF OFFICERS AND DIRECTORS
                   -----------------------------------------

          Section 1.  (a) The corporation shall indemnify any person who was or
is a party or is threatened to be made a party to any threatened, pending or
completed action, suit or proceeding, whether civil, criminal, administrative or
investigative (other than an action by or in the right of the corporation) by
reason of the fact that he is or was a director, officer, employee or agent of
the corporation, or is or was serving at the request of the corporation as a
director, officer, employee or agent of another corporation, partnership, joint
venture, trust or other enterprise, against expenses (including attorneys'
fees), judgments, fines and amounts paid in settlement actually and reasonably
incurred by him in connection with such action, suit or proceeding if he acted
in good faith and in a manner he reasonably believed to be in or not opposed to
the best interests of the corporation, and with respect to any criminal action
or proceeding, had no reasonable cause to believe his conduct was unlawful. The
termination of any action, suit or

                                      15
<PAGE>
 
proceeding by judgment, order, settlement, conviction or upon a plea of nolo
contenders or its equivalent, shall not, of itself, create a presumption that
the person did not act in good faith and in a manner which he reasonably
believed to be in or not opposed to the best interests of the corporation, and,
with respect to any criminal action or proceeding, had reasonable cause to
believe that his conduct was unlawful.

          (b) The corporation shall indemnify any person who was or is a party
or is threatened to be made a party to any threatened, pending or completed
action or suit by or in the right of the corporation to procure a judgment in
its favor by reason of the fact that he is or was a director, officer, employee
or agent of the corporation, or is or was serving at the request of the
corporation as a director, officer, employee or agent of another corporation,
partnership, joint venture, trust or other enterprise against expenses
(including attorneys' fees) actually and reasonably incurred by him in
connection with the defense or settlement of such action or suit if he acted in
good faith and in a manner he reasonably believed to be in or not opposed to the
best interests of the corporation and except that no indemnification shall be
made in respect of any claim, issue or matter as to which such person shall have
been adjudged to be liable to the corporation unless and only to the extent that
the Court of Chancery or the court in which such action or suit was brought
shall determine upon application that, despite the adjudication of liability but
in view of all the circumstances of the case, such person is fairly and
reasonably entitled to indemnity for such expenses which the Court of Chancery
or such other court shall deem proper.

          (c) To the extent that a director, officer, employee or agent of the
corporation has been successful on the merits or otherwise in defense of any
action, suit or proceeding referred to in subsection (a) or (b), or in defense
of any claim, issue or matter therein, he shall be indemnified against expenses
(including attorneys, fees) actually and reasonably incurred by him in
connection therewith.

          (d) Any indemnification under subsection (a) or (b) (unless ordered by
a court) shall be made by the corporation only as authorized in the specific
case upon a determination that indemnification of the director, officer,
employee or agent is proper in the circumstances because he has met the
applicable standard of conduct set forth in subsections (a) and (b).  Such
determination shall be made (1) by the Board of Directors by a majority vote of
a quorum consisting of directors who were not parties to such action, suit or
proceeding, or (2) if such a  quorum is not obtainable, or, even if obtainable a
quorum of disinterested directors so directs, by independent legal counsel in a
written opinion, or (3) by the stockholders.

          (e) Expenses (including attorneys' fees incurred in defending any
civil, criminal, administrative or investigative action, suit or proceeding
shall be paid by the corporation in advance of the final disposition of such
action, suit or proceeding upon receipt of an undertaking by or on behalf of the
director, officer, employee or agent to repay such amount if it shall ultimately
be determined that he is not entitled to be indemnified by the corporation as
authorized in this section.

          (f) The indemnification and advancement of expenses provided by or
granted pursuant to this section shall not be deemed exclusive of any other
rights to which those seeking indemnification or advancement of expenses may be
entitled under the certificate of incorporation or any agreement, vote of
stockholders or disinterested directors or otherwise, both

                                      16
<PAGE>
 
as to action in his official capacity and as to action in another capacity while
holding such office, and shall continue as to a person who has ceased to be a
director, officer, employee or agent and shall inure to the benefit of the
heirs, executors and administrators of such a person.

          (g) The corporation shall have power to purchase and maintain
insurance on behalf of any person who is or was a director, officer, employee or
agent of the corporation, or is or was serving at the request of the corporation
as a director, officer, employee or agent of another corporation, partnership,
joint venture, trust or other enterprise against any liability asserted against
him and incurred by him in any such capacity, or arising out of his status as
such, whether or not the corporation would have the power to indemnify him
against such liability under the provisions or this section.

          (h) For purposes of this section, references to "the corporation"
shall include, in addition to the resulting corporation, any constituent
corporation (including any constituent of a constituent) absorbed in a
consolidation or merger which, if its separate existence had continued, would
have had power and authority to indemnify its directors, officers, and employees
or agents, so that any person who is or was a director, officer, employee or
agent of such constituent corporation, or is or was serving at the request of
such constituent corporation as a director, officer, employee or agent of
another corporation, partnership, joint venture, trust or other enterprise,
shall stand in the same position under the provisions of this section with
respect to the resulting or surviving corporation as he would have with respect
to such constituent corporation if its separate existence had continued.

                   INTERESTED DIRECTORS AND OFFICERS; QUORUM
                   -----------------------------------------

          Section 2. No contract or transaction between the corporation and one
or more of its directors or officers, or between the corporation and any other
corporation, partnership, association or other organization in which one or more
of its directors or officers are directors or officers or have a financial
interest, shall be void or voidable solely for this reason, or solely because
the director or officer is present at or participates in the meeting of the
Board of Directors or committee thereof which authorizes the contract or
transaction, or solely because his or their votes are counted for such purpose,
if (i) the material facts as to his relationship or interest and as to the
contract or transaction are disclosed or are known to the Board or the
committee, and the Board or committee in good faith authorizes the contract or
transaction by the affirmative votes of a majority of the disinterested
directors, even though the disinterested directors be less than a quorum; or
(ii) the material facts as to his relationship or interest and as to the
contract or transaction are disclosed or are known to the stockholders entitled
to vote thereon, and the contract or transaction is specifically approved in
good faith by vote of the stockholders; or (iii) the contract or transaction is
fair as to the corporation as of the time it is authorized, approved or ratified
by the Board, a committee thereof or the stockholders. Common or interested
directors may be counted in determining the presence of a quorum at a meeting of
the Board or of a committee which authorizes the contract or transaction.

                                   DIVIDENDS
                                   ---------

          Section 3. Dividends upon the capital stock of the corporation,
subject to the provisions of the certificate of incorporation, may be declared
by the Board of Directors at any regular or special meeting, pursuant to law.
Dividends may be paid in cash, in property, or in

                                      17
<PAGE>
 
shares of the capital stock, subject to the provisions of the certificate of
incorporation.

          Section 4. Before payment of any dividend, there may be set aside out
of any funds of the corporation available for dividends such sum or sums as the
directors from time to time, in their absolute discretion, think proper as a
reserve or reserves to meet contingencies, or for equalizing dividends, or for
repairing or maintaining any property of the corporation, or for such other
purpose as the directors shall think conducive to the interest of the
corporation, and the directors may modify or abolish any such reserve in the
manner in which it was created.


                                    CHECKS
                                    ------

          Section 5. All checks or demands for money and notes of the
corporation shall be signed by such officer or officers or such other person or
persons as authorized by these bylaws or the Board of Directors may from time to
time designate.

                                  FISCAL YEAR
                                  -----------

          Section 6.  The fiscal year of the corporation shall be fixed by
resolution of the Board of Directors.

                                     SEAL
                                     ----
          Section 7.  The corporate seal shall have inscribed thereon the name
of the corporation and shall be in such form as may be approved from time to
time by the Board of Directors.  The seal may be used by causing it or a
facsimile thereof to be impressed, affixed, imprinted or in any manner
reproduced.


                                 ARTICLE VIII.

                                  AMENDMENTS
                                  ----------

          These bylaws may be altered, amended or repealed or new bylaws may be
adopted by the stockholders or by the Board of Directors at any regular meeting
of the stockholders or of the Board of Directors or at any special meeting of
the stockholders or of the Board of Directors if notice of such alteration,
amendment, repeal or adoption of new bylaws be contained in the notice of such
special meeting.

                                      18
<PAGE>
 
                           AMENDMENT OF THE BY-LAWS


          Section 1 of Article V of the By-Laws shall be deleted in its entirety
and replaced, in lieu thereof, by the following:

          "Section 1.  The officers of the corporation shall be chosen by the
Board of Directors and shall consist of: (i) a chairman of the board and chief
executive officer (who shall be a member of the Board of Directors); (ii) a
president and chief operating officer; (iii) one or more vice presidents; (iv) a
secretary; (v) a treasurer; and (vi) such other officers, with such duties, as
the Board of Directors shall direct."



Adopted by the Board of Directors
on September 6, 1996