<PAGE>

                              AMENDED AND RESTATED
                          CERTIFICATE OF INCORPORATION
                                       OF
                               COMMERCE ONE, INC.

                    (Pursuant to Sections 242 and 245 of the
                General Corporation Law of the State of Delaware)

     Mark B. Hoffman and Robert M. Tarkoff each hereby certifies:

     (1) They are the President and Secretary, respectively, of Commerce One,
Inc., a corporation organized and existing under the General Corporation Law of
the State of Delaware (the "General Corporation Law");

     (2) The original Certificate of Incorporation of this corporation,
originally filed on March 24, 1999, is hereby amended and restated in its
entirety to read as follows:

FIRST:         The name of this corporation is Commerce One, Inc. (the
               "Corporation").

SECOND:        The address of the Corporation's registered office in the State
               of Delaware is 1209 Orange Street, Wilmington, County of New
               Castle, Delaware 19801. The name of its registered agent at such
               address is Corporation Service Company.

THIRD:         The purpose of the Corporation is to engage in any lawful act or
               activity for which corporations may be organized under the
               General Corporation Law of Delaware.

FOURTH:        The Corporation is authorized to issue two classes of stock to be
               designated respectively Common Stock and Preferred Stock. The
               total number of shares of all classes of stock which the
               Corporation has authority to issue is Two Hundred Sixty Million
               (260,000,000), consisting of Two Hundred Fifty Million
               (250,000,000) shares of Common Stock, $0.0001 par value (the
               "Common Stock"), and Ten Million (10,000,000) shares of Preferred
               Stock, $0.0001 par value (the "Preferred Stock").

               The Preferred Stock may be issued from time to time in one or
               more series. The Board of Directors is hereby authorized subject
               to limitations prescribed by law, to fix by resolution or
               resolutions the designations, powers, preferences and rights, and
               the qualifications, limitations or restrictions thereof, of each
               such series of Preferred Stock, including without limitation
               authority to fix by resolution or resolutions, the dividend
               rights, dividend rate, conversion rights, voting rights, rights
               and terms of redemption (including sinking fund provisions),
               redemption price or prices, and liquidation
<PAGE>

               preferences of any wholly unissued series of Preferred Stock, and
               the number of shares constituting any such series and the
               designation thereof, or any of the foregoing.

               The Board of Directors is further authorized to increase (but not
               above the total number of authorized shares of the class) or
               decrease (but not below the number of shares of any such series
               then outstanding) the number of shares of any series, the number
               of which was fixed by it, subsequent to the issue of shares of
               such series then outstanding, subject to the powers, preferences
               and rights, and the qualifications, limitations and restrictions
               thereof stated in the resolution of the Board of Directors
               originally fixing the number of shares of such series. If the
               number of shares of any series is so decreased, then the shares
               constituting such decrease shall resume the status which they had
               prior to the adoption of the resolution originally fixing the
               number of shares of such series.

FIFTH:         The Corporation is to have perpetual existence.

SIXTH:         The election of directors need not be by written ballot unless
               the Bylaws of the Corporation shall so provide.

SEVENTH:       The number of directors which constitute the whole Board of
               Directors of the Corporation shall be designated in the Bylaws of
               the Corporation.

EIGHTH:        In furtherance and not in limitation of the powers conferred by
               the laws of the State of Delaware, the Board of Directors is
               expressly authorized to adopt, alter, amend or repeal the Bylaws
               of the Corporation.

NINTH:         To the fullest extent permitted by the Delaware General
               Corporation Law as the same exists or may hereafter be amended,
               no director of the Corporation shall be personally liable to the
               Corporation or its stockholders for monetary damages for breach
               of fiduciary duty as a director.

               The Corporation may indemnify to the fullest extent permitted by
               law any person made or threatened to be made a party to an action
               or proceeding, whether criminal, civil, administrative or
               investigative, by reason of the fact that he, his testator or
               intestate is or was a director, officer or employee of the
               Corporation or any predecessor of the Corporation or serves or
               served at any other enterprise as a director, officer or employee
               at the request of the Corporation or any predecessor to the
               Corporation.

               Neither any amendment nor repeal of this Article, nor the
               adoption of any provision of this Amended and Restated
               Certificate of Incorporation inconsistent with this Article,
               shall eliminate or reduce the effect of this Article in respect
               of any matter occurring, or any cause of action, suit or claim


                                      -2-
<PAGE>

               that, but for this Article, would accrue or arise, prior to such
               amendment, repeal or adoption of an inconsistent provision.

TENTH:         At the election of directors of the Corporation, each holder of
               stock of any class or series shall be entitled to one vote for
               each share held. No stockholder will be permitted to cumulate
               votes at any election of directors.

               The number of directors which constitute the whole Board of
               Directors of the Corporation shall be fixed exclusively by one or
               more resolution adopted from time to time by the Board of
               Directors. The Board of Directors shall be divided into three
               classes designated as Class I, Class II, and Class III,
               respectively. Directors shall be assigned to each class in
               accordance with a resolution or resolutions adopted by the Board
               of Directors. At the first annual meeting of stockholders
               following the date hereof, the term of office of the Class I
               directors shall expire and Class I directors shall be elected for
               a full term of three years. At the second annual meeting of
               stockholders following the date hereof, the term of office of the
               Class II directors shall expire and Class II directors shall be
               elected for a full term of three years. At the third annual
               meeting of stockholders following the date hereof, the term of
               office of the Class III directors shall expire and Class III
               directors shall be elected for a full term of three years. At
               each succeeding annual meeting of stockholders, directors shall
               be elected for a full term of three years to succeed the
               directors of the class whose terms expire at such annual meeting.

               Vacancies created by newly created directorships, created in
               accordance with the Bylaws of this Corporation, may be filled by
               the vote of a majority, although less than a quorum, of the
               directors then in office, or by a sole remaining director.

ELEVENTH:      Meetings of stockholders may be held within or without the State
               of Delaware, as the Bylaws may provide. The books of the
               Corporation may be kept (subject to any provision contained in
               the laws of the State of Delaware) outside of the State of
               Delaware at such place or places as may be designated from time
               to time by the Board of Directors or in the Bylaws of the
               Corporation.

               The stockholders of the Corporation may not take any action by
               written consent in lieu of a meeting, and must take any actions
               at a duly called annual or special meeting of stockholders and
               the power of stockholders to consent in writing without a meeting
               is specifically denied.

TWELFTH:       Advance notice of new business and stockholder nominations for
               the election of directors shall be given in the manner and to the
               extent provided in the Bylaws of the Corporation.


                                      -3-
<PAGE>

THIRTEENTH:    Notwithstanding any other provisions of this Restated Certificate
               of Incorporation or any provision of law which might otherwise
               permit a lesser vote or no vote, but in addition to any
               affirmative vote of the holders of the capital stock required by
               law or this Restated Certificate of Incorporation, the
               affirmative vote of the holders of at least two-thirds (2/3) of
               the combined voting power of all of the then-outstanding shares
               of the Corporation entitled to vote shall be required to alter,
               amend or repeal Articles NINTH, TENTH, ELEVENTH or TWELFTH
               hereof, or this Article THIRTEENTH, or any provision thereof or
               hereof, unless such amendment shall be approved by a majority of
               the directors of the Corporation.

FOURTEENTH:    The Corporation reserves the right to amend, alter, change or
               repeal any provision contained in this Amended and Restated
               Certificate of Incorporation, in the manner now or hereafter
               prescribed by the laws of the State of Delaware, and all rights
               conferred herein are granted subject to this reservation.

     (3) This Amended and Restated Certificate of Incorporation has been duly
adopted by the Board of Directors of this Corporation in accordance with
Sections 242 and 245 of the General Corporation Law.

     (4) This Amended and Restated Certificate of Incorporation has been duly
approved, in accordance with Section 242 of the General Corporation Law, by vote
of the holders of a majority of the outstanding stock entitled to vote thereon.

     IN WITNESS WHEREOF, the undersigned have executed this Amended and Restated
Certificate of Incorporation on this 7th day of July, 1999.

                                                        /s/ Mark Hoffman
                                                        ----------------
                                                        Mark B. Hoffman
                                                        President

/s/ Robert M. Tarkoff
---------------------
Robert M. Tarkoff
Secretary


                                      -4-