<PAGE>   1
                                                                    EXHIBIT 2.2

                    FIRST AMENDMENT TO AMENDED AND RESTATED
                          AGREEMENT AND PLAN OF MERGER


                 THIS FIRST AMENDMENT TO AMENDED AND RESTATED AGREEMENT AND
PLAN OF MERGER, dated as of April 14, 1997 (this "Amendment"), is by and among
Enron Corp., a Delaware corporation ("Enron"), Portland General Corporation, an
Oregon corporation ("PGC"), and Enron Oregon Corp. (formerly New Falcon Corp.),
an Oregon corporation and wholly owned subsidiary of Enron (the "Company").

                 WHEREAS, the parties hereto have entered into that certain
Amended and Restated Agreement and Plan of Merger, dated as of July 20, 1996
and amended and restated as of September 24, 1996 (as amended hereby, the
"Agreement") (capitalized terms used but not defined herein shall have the
respective meanings ascribed to such terms in the Agreement);

                 WHEREAS, the Mergers and the transactions contemplated by the
Agreement have been approved by the holders of Enron Common Stock at the Enron
Special Meeting and by the holders of the PGC Common Stock at the PGC Special
Meeting, each of which meetings was held on November 12, 1996;

                 WHEREAS, the Mergers and the transactions contemplated by the
Agreement have received all regulatory approvals required in connection
therewith, with the exception of the approval of the OPUC;

                 WHEREAS, the parties desire to amend certain provisions of the
Agreement in order to facilitate receipt of OPUC's approval of Enron's merger
approval application; and

                 WHEREAS, the boards of directors of Enron and PGC have
approved and deemed it advisable and in the best interests of their respective
shareholders to consummate the transactions on the terms set forth in the
Agreement, as amended hereby;

                 NOW THEREFORE, in consideration of the foregoing and the
respective representations, warranties, covenants and agreements contained
herein, the parties hereto agree as follows:

         1.      Section 2.2(b) of the Agreement is hereby amended so that the
first sentence thereof is deleted and replaced with the following:

         Each share of PGC Common Stock issued and outstanding immediately
         prior to the Second Effective Time (other than shares canceled
         pursuant to Section 2.2(a)) shall be converted into 0.9825 shares of
         Company Common Stock (the "PGC Conversion Ratio").

         2.      Sections 2.5(b) and (c) of the Agreement are hereby amended by
replacing each reference to "$41.75" with a reference to "$40.25."  The parties
acknowledge that although Section 2.5 also contains provisions relating to the
adjustment of the Ceiling Price and the Floor Price, the





<PAGE>   2

parties agree that the provisions of the Agreement relating to the Ceiling
Price and the Floor Price ceased to be applicable upon the obtaining of the PGC
Shareholders' Approval and the Enron Shareholders' Approval.
        
         3.      The parties acknowledge that references in the Agreement to
the term "as of the date hereof," or "as of the date of this Agreement" shall
continue to refer to July 20, 1996, unless otherwise specified.  Unless
otherwise specified, each reference in the Agreement (or in any other document
referring to the Agreement) to "this Agreement" shall be to the Agreement, as
amended hereby.

         4.      Section 4.8 of the Agreement is hereby amended to read in its
entirety as follows, and shall be deemed to be made as of the date of this
Amendment:

                 Section 4.8      Registration Statement and Proxy Statement.
         None of the information supplied or to be supplied by or on behalf of
         Enron that is included or incorporated by reference in (i) (A) the
         registration statement on Form S-4 to be filed with the SEC by the
         Company in connection with the issuance of shares of Company Common
         Stock in the PGC Merger (the "Registration Statement") or (B) the
         Post-Effective Amendment (as defined in Section 7.2(a)) will, at the
         time the Registration Statement or the Post-Effective Amendment
         becomes effective under the Securities Act, contain any untrue
         statement of a material fact or omit to state any material fact
         required to be stated therein or necessary to make the statements
         therein not misleading, (ii) the joint proxy statement/prospectus in
         definitive form, relating to the meetings of the shareholders of PGC
         and Enron to be held in connection with the Mergers and the prospectus
         relating to the Company Common Stock to be issued in the PGC Merger
         (the "Joint Proxy Statement") will, at the date such document is
         mailed to such shareholders and, as the same may be amended or
         supplemented, at the times of such meetings, contain any untrue
         statement of a material fact or omit to state any material fact
         necessary in order to make the statements therein, in light of the
         circumstances under which they are made, not misleading and (iii) the
         Supplemental Proxy Statement (as defined in Section 7.20(a)) in
         definitive form, relating to the Supplemental PGC Shareholders'
         Meeting (as defined in Section 7.20(e)) will, at the date such
         document is mailed to the shareholders of PGC and, as the same may be
         amended or supplemented, at the times of such meeting, contain any
         untrue statement of a material fact or omit to state any material fact
         necessary in order to make the statements therein, in light of the
         circumstances under which they are made, not misleading.   All
         documents that Enron is responsible for filing with the SEC in
         connection with the transactions contemplated herein shall comply as
         to form in all material respects with the applicable requirements of
         the Securities Act and the rules and regulations thereunder and the
         Exchange Act and the rules and regulations thereunder.




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         5.       Article IV of the Agreement is hereby amended by adding the 
following representations, which are made as of the date of this Amendment:

                 Section 4.18     Authority, Non-Contravention and Statutory
         Approvals relating to the Agreement As Amended by the First Amendment.

                 (a)      Authority.  Enron and the Company have all requisite
         power and authority to enter into the First Amendment (as defined in
         Section 4.19) and, subject to obtaining the Enron Required Statutory
         Approvals, to consummate the transactions contemplated by this
         Agreement.  The execution and delivery of the First Amendment and the
         consummation by Enron and the Company of the transactions contemplated
         by this Agreement have been duly authorized by all necessary corporate
         action on the part of Enron or the Company, as the case may be.  The
         First Amendment has been duly and validly executed and delivered by
         Enron and the Company and, assuming the due authorization, execution
         and delivery of this Agreement by PGC, the Agreement constitutes the
         legal, valid and binding obligation of Enron and the Company,
         enforceable against Enron and the Company in accordance with its
         terms.

                 (b)      Non-Contravention.  Except as disclosed in Section
         4.4(b) of the Enron Disclosure Schedule, the execution and delivery of
         the First Amendment by Enron do not, and the consummation of the
         transactions contemplated by this Agreement will not, result in an
         Enron Violation under any provisions of (i) the certificate of
         incorporation, bylaws or similar charter documents of Enron or any of
         its subsidiaries or, to Enron's knowledge, any of its joint ventures,
         (ii) subject to obtaining the Enron Required Statutory Approvals, any
         statute, law, ordinance, rule, regulation, judgment, decree, order,
         injunction, writ, permit or license of any Governmental Authority,
         applicable to Enron or any of its subsidiaries or, to Enron's
         knowledge, any of its joint ventures, or any of their respective
         properties or assets or (iii) subject to obtaining the Enron Required
         Consents, any note, bond, mortgage, indenture, deed of trust, license,
         franchise, permit, concession, contract, lease or other instrument,
         obligation or agreement of any kind to which Enron or any of its
         subsidiaries or, to Enron's knowledge, any of its joint ventures, is
         now a party or by which any of them or any of their respective
         properties or assets may be bound or affected, excluding from the
         foregoing clauses (ii) and (iii) such Enron Violations as would not
         have, in the aggregate, an Enron Material Adverse Effect.

                 (c)      Statutory Approvals.  Except for (i) the OPUC
         Approval (as defined in Section 7.3(a)), (ii) a declaration of
         effectiveness by the SEC of the Post-Effective Amendment (as defined
         in Section 7.2), (iii) the matters set forth in items (c) and (f) on
         Section 4.4(c) of the Enron Disclosure Schedule, (iv) those
         declarations, filings, registrations, notices, authorizations,
         consents, findings or approvals that have already been made and (v)
         any supplemental filings relating to any of the foregoing required by
         the execution of the First Amendment or the transactions contemplated
         thereby, there are no Enron Required Statutory Approvals in connection
         with the execution and delivery of the First Amendment





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<PAGE>   4

         by Enron and the Company or the consummation by Enron and the Company
         of the transactions contemplated by this Agreement the failure to
         obtain, make or give which would have, in the aggregate, an Enron
         Material Adverse Effect.

                 Section 4.19     Vote Required for First Amendment.  No
         additional vote by the holders of any capital stock of Enron is
         required in connection with the First Amendment to this Agreement,
         which amendment was executed as of April 14, 1997 (the "First
         Amendment").

         6.      Section 5.8 of the Agreement is hereby amended to read in its
entirety as follows, and shall be deemed to be made by PGC as of the date of
this Amendment:

                 Section 5.8      Registration Statement and Proxy Statement.
         None of the information supplied or to be supplied by or on behalf of
         PGC that is included or incorporated by reference in (i) (A) the
         Registration Statement or (B) the Post-Effective Amendment will, at
         the time the Registration Statement or the Post-Effective Amendment
         becomes effective under the Securities Act, contain any untrue
         statement of a material fact or omit to state any material fact
         required to be stated therein or necessary to make the statements
         therein not misleading, (ii) the Joint Proxy Statement will, at the
         date that document is mailed to the shareholders of PGC and Enron and,
         as the same may be amended or supplemented, at the times of the
         meetings of such shareholders to be held in connection with the
         Merger, contain any untrue statement of a material fact or omit to
         state any material fact necessary in order to make the statements
         therein, in light of the circumstances under which they are made, not
         misleading and (iii) the Supplemental Proxy Statement will, at the
         date that document is mailed to the shareholders of PGC and, as the
         same may be amended or supplemented, at the time of the Supplemental
         PGC Shareholders Meeting contain any untrue statement of a material
         fact or omit to state any material fact necessary in order to make the
         statements therein, in light of the circumstances under which they are
         made, not misleading.  All documents that PGC is responsible for
         filing with the SEC in connection with the transactions contemplated
         herein shall comply as to form in all material respects with the
         applicable requirements of the Securities Act and the rules and
         regulations thereunder and the Exchange Act and the rules and
         regulations thereunder.

         7.      Article V of the Agreement is hereby amended by adding the
following representations, which are made as of the date of this Amendment:

                 Section 5.18     Authority, Non-Contravention and Statutory
         Approvals relating to the Agreement As Amended by the First Amendment.

                 (a)      Authority.  PGC has all requisite power and authority
         to enter into the First Amendment and, subject to the Supplemental PGC
         Shareholders' Approval (as defined in Section 5.19) and the PGC
         Required Statutory Approvals, to consummate the transactions
         contemplated by this Agreement.  The execution and delivery of the
         First Amendment and





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         the consummation by PGC of the transactions contemplated by this
         Agreement and thereby have been duly authorized by all necessary
         corporate action on the part of PGC, subject to obtaining the
         Supplemental PGC Shareholders' Approval.  The First Amendment has been
         duly and validly executed and delivered by PGC and, assuming the due
         authorization, execution and delivery hereof by Enron and the Company,
         constitutes the legal, valid and binding obligation of PGC enforceable
         against PGC in accordance with its terms.

                 (b)      Non-Contravention.  Except as disclosed in Section
         5.4(b) of the PGC Disclosure Schedule, the execution and delivery of
         the First Amendment by PGC do not, and the consummation of the
         transactions contemplated by this Agreement will not, result in a PGC
         Violation under any provisions of (i) the articles of incorporation,
         bylaws or similar governing documents of PGC or any of its
         subsidiaries or joint ventures, (ii) subject to obtaining the PGC
         Required Statutory Approvals and the Supplemental PGC Shareholders'
         Approval, any statute, law, ordinance, rule, regulation, judgment,
         decree, order, injunction, writ, permit or license of any Governmental
         Authority applicable to PGC or any of its subsidiaries or joint
         ventures or any of their respective properties or assets, or (iii)
         subject to obtaining PGC Required Consents, any note, bond, mortgage,
         indenture, deed of trust, license, franchise, permit, concession,
         contract, lease or other instrument, obligation or agreement of any
         kind to which PGC or any of its subsidiaries or joint ventures is now
         a party or by which any of them or any of their respective properties
         or assets may be bound or affected, excluding from the foregoing
         clauses (ii) and (iii) such PGC Violations as would not have, in the
         aggregate, a PGC Material Adverse Effect.

                 (c)      Statutory Approvals. Except for (i) the OPUC
         Approval, (ii) a declaration of effectiveness by the SEC of the
         Post-Effective Amendment, (iii) the matters set forth in items (5) and
         (6) on Section 5.4(c) of the PGC Disclosure Schedule, (iv) those
         declarations, filings, registrations, notices, authorizations,
         consents, findings or approvals that have already been made and (v)
         any supplemental filings relating to any of the foregoing required by
         the execution of the First Amendment or the transactions contemplated
         thereby, there are no PGC Required Statutory Approvals in connection
         with the execution and delivery of the First Amendment by PGC or the
         consummation by PGC of the transactions contemplated by this
         Agreement, the failure to obtain, make or give which would have, in
         the aggregate, a PGC Material Adverse Effect.

                 Section 5.19     Vote Required for First Amendment.  The
         approval of the First Amendment and the PGC Merger by the holders of a
         majority of the shares of outstanding PGC Common Stock (the
         "Supplemental PGC Shareholders' Approval") is the only vote of the
         holders of any class or series of the capital stock of PGC required to
         approve this Agreement (as amended by the First Amendment), the PGC
         Merger and the other transactions contemplated by this Agreement.

                 Section 5.20     Supplemental Opinion of Financial Advisor.
         PGC has received the opinion of Goldman, Sachs & Co. dated the date of
         the First Amendment to the effect that,





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<PAGE>   6

         as of such date, the consideration to be received by the holders of
         PGC Common Stock in the PGC Merger pursuant to this Agreement (as
         amended by the First Amendment) is fair from a financial point of view
         to the holders of PGC Common Stock.

         8.      Section 7.3(a) of the Agreement is hereby amended to read in
its entirety as follows:

                          (a)     Regulatory Plans.  Set forth on Appendix I
                 are the terms of the revised regulatory plan to be submitted
                 for approval by the OPUC (the "Revised OPUC Plan").  To the
                 extent that the regulatory plans set forth in Schedule 7.3(a)
                 (the "Regulatory Plans") relate to the OPUC or the state
                 regulatory approval process, such regulatory plans (and
                 Schedule 7.3(a)) are hereby amended to reflect the Revised
                 OPUC Plan.  The approval of the OPUC contemplated by the
                 Revised OPUC Plan is referred to herein as the "OPUC
                 Approval." PGC and Enron shall cooperate in good faith,
                 consult with each other and obtain each other's consent and
                 agreement (which shall not be unreasonably withheld) on all
                 components of, significant steps toward the achievement of the
                 Revised OPUC Plan and obtaining the OPUC Approval and with
                 respect to significant filings, communications, agreements,
                 arrangements or consents, written or oral, formal or informal,
                 with the OPUC and/or any intervenor or representative thereof.

         9.      Article VII of the Agreement is hereby amended by adding
Section 7.20, which shall read as follows:

                 Section 7.20     PGC Supplemental Proxy Statement and
         Registration Statement.

                 (a)      Preparation and Filing.  As promptly as reasonably
         practicable after the date of the First Amendment, the parties shall
         prepare and file with the SEC a post-effective amendment to the
         Registration Statement and a Proxy Statement (the "Supplemental Proxy
         Statement") in connection with the Supplemental PGC Shareholders'
         Meeting. The parties shall take such actions as may be reasonably
         required to cause the post-effective amendment to the Registration
         Statement (the "Post-Effective Amendment") to be declared effective
         under the Securities Act as promptly as practicable after such filing.
         The parties shall also take such action as may be reasonably required
         to cause the shares of Company Common Stock and Company Preferred
         Stock issuable in connection with the Mergers to be registered under
         or to obtain an exemption from registration under applicable state
         "blue sky" or securities laws, and to promptly make any filings
         required in connection with the First Amendment and the transactions
         contemplated thereby; provided, however, that none of the Company, PGC
         or Enron shall be required to register or qualify as a foreign
         corporation or to take any other action that would subject it to
         general service of process in any jurisdiction in which the Company
         will not, following the Effective Time, be so subject.  Each of the
         parties shall furnish all information concerning itself that is
         required or customary for inclusion in the Supplemental Proxy
         Statement and/or the Post-Effective Amendment.  If, at any time prior
         to the Effective Time, Enron discovers any event or circumstance
         relating





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         to Enron or any of its subsidiaries, or its or their respective
         officers or directors, that should be set forth in an amendment to the
         Post-Effective Amendment or a supplement to the Supplemental Proxy
         Statement, Enron shall promptly inform PGC.  If, at any time prior to
         the Effective Time, PGC discovers any event or circumstance relating
         to PGC or any of its subsidiaries, or its or their respective officers
         or directors that should be set forth in an amendment to the
         Post-Effective Amendment or a supplement to the Supplemental Proxy
         Statement, PGC shall promptly inform Enron. No representation,
         covenant or agreement contained in this Agreement is made by any party
         hereto with respect to information supplied by any other party hereto
         for inclusion in the Post-Effective Amendment or the Supplemental
         Proxy Statement.  The Post-Effective Amendment and the Supplemental
         Proxy Statement shall comply as to form in all material respects with
         the Securities Act and the rules and regulations thereunder.

                 (b)      Letter of Enron's Accountants.  Following receipt by
         Arthur Andersen LLP, Enron's independent auditors, of an appropriate
         request from PGC pursuant to SAS No. 72, Enron shall use best efforts
         to cause to be delivered to the Company and PGC a letter of Arthur
         Andersen LLP, dated a date within two business days before the
         effective date of the Post-Effective Amendment and addressed to the
         Company and PGC, in form and substance reasonably satisfactory to the
         Company and PGC and customary in scope and substance for "cold
         comfort" letters delivered by independent public accountants in
         connection with registration statements and proxy statements similar
         to the Post-Effective Amendment and the Supplemental Proxy Statement.

                 (c)      Letter of PGC's Accountants.  Following receipt by
         Arthur Andersen LLP, PGC's independent auditors, of an appropriate
         request from Enron pursuant to SAS No. 72, PGC shall use best efforts
         to cause to be delivered to the Company and Enron a letter of Arthur
         Andersen LLP dated a date within two business days before the
         effective date of the Post-Effective Amendment and addressed to the
         Company and Enron, in form and substance satisfactory to the Company
         and Enron and customary in scope and substance for "cold comfort"
         letters delivered by independent public accountants in connection with
         registration statements and proxy statements similar to the
         Post-Effective Amendment and the Supplemental Proxy Statement.

                 (d)      Fairness Opinion.  Prior to mailing the Supplemental
         Proxy Statement to the shareholders of PGC, PGC shall have received an
         opinion from Goldman, Sachs & Co., dated the date of the Supplemental
         Proxy Statement, to the effect that, as of the date thereof, the
         consideration to be received by holders of PGC Common Stock pursuant
         to the PGC Merger is fair to such holders from a financial point of
         view.

                 (e)      Supplemental PGC Shareholder Approval.  PGC shall, as
         promptly as reasonably practicable after the date of the First
         Amendment (i) take all steps reasonably necessary to call, give notice
         of, convene and hold a meeting of its shareholders, which may be
         either a special meeting or annual meeting (the "Supplemental PGC
         Shareholders"





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         Meeting"), for the purpose of securing the Supplemental PGC
         Shareholders' Approval, (ii) distribute to its shareholders the
         Supplemental Proxy Statement in accordance with applicable federal and
         state law and with its articles of incorporation and bylaws, which
         Supplemental Proxy Statement shall contain the recommendation of the
         Board of Directors of PGC that its shareholders approve the PGC
         Merger, this Agreement and the transactions contemplated by this
         Agreement (as amended by the First Amendment), (iii) use all
         reasonable efforts to solicit from its shareholders proxies in favor
         of the approval and adoption of the PGC Merger this Agreement (as
         amended by the First Amendment) and the transactions contemplated by
         this Agreement and to secure the Supplemental PGC Shareholders'
         Approval, and (iv) cooperate and consult with Enron with respect to
         each of the foregoing matters; provided, that nothing contained in
         this Section 7.20(a) shall prohibit the PGC Board of Directors from
         failing to make or from withdrawing or modifying its recommendation to
         the PGC shareholders hereunder if the Board of Directors of PGC, after
         consultation with and based upon the written advice of independent
         legal counsel, determines in good faith that such action is necessary
         for such Board of Directors to comply with its fiduciary duties to its
         shareholders under applicable law.

         10.     Sections 7.12, 9.1(f) and 9.3 of the Agreement are hereby
amended to (a) replace each reference to "PGC Special Meeting" with
"Supplemental PGC Shareholders' Meeting" and (b) replace each reference to "PGC
Shareholders' Approval" with "Supplemental PGC Shareholders' Approval."

         11.     Section 7.18 of the Agreement is hereby amended to read in its
entirety as follows:

                 Section 7.18     Expenses.  Subject to Section 7.1 and Section
         9.3, all costs and expenses incurred in connection with this Agreement
         and the transactions contemplated hereby and thereby shall be paid by
         the party incurring such expenses, except that those expenses incurred
         in connection with printing the Joint Proxy/Registration Statement,
         the Post-Effective Amendment and the Supplemental Proxy Statement, as
         well as the filing fee relating thereto, shall be shared equally by
         Enron, on the one hand, and PGC, on the other hand.

         12.     Section 8.1(a) of the Agreement is hereby amended to read in
its entirety as follows:

                 (a)      Shareholder Approvals.  The PGC Shareholders'
         Approval, the Supplemental PGC Shareholder Approval and the Enron
         Shareholders' Approval shall have been obtained.

         13.     Section 8.1(c) of the Agreement is hereby amended to read in 
its entirety as follows:

                 (c)      Registration Statement and Post-Effective Amendment.
         The Registration Statement and the Post-Effective Amendment shall
         have become effective in accordance with the provisions of the
         Securities Act, and no stop order suspending such effectiveness shall
         have been issued and remain in effect.





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         14.     The second sentence of Section 8.1(e) of the Agreement is
hereby amended to read in its entirety as follows:

         A "Final Order" means action by the relevant regulatory authority that
         has not been reversed, stayed, enjoined, set aside, annulled or
         suspended, with respect to which any waiting period prescribed by law
         before the transactions contemplated hereby may be consummated has
         expired (but without the requirement for expiration of any applicable
         appeal period), and as to which all conditions to the consummation of
         such transactions prescribed by law, regulation or order have been
         satisfied.

         15.     Section 8.2(f) of the Agreement is hereby amended to read in
its entirety as follows:

                 (f)      Approval of Regulatory Plans. The OPUC shall have
         issued a Final Order that approves the Revised OPUC Plan that (i) does
         not include the imposition or threatened imposition of any change to
         the payment obligations, direct or indirect, of PGC, Enron or any
         affiliate of either of them set forth in Sections 2(19) and 2(20) of
         Appendix I, (ii) adopts the conditions set forth in Appendix I
         (including those set forth in Sections 2(19) and 2(20)), substantially
         in the form set forth in Appendix I, and (iii) does not include the
         imposition or threatened imposition of any other conditions that are
         substantive.  For purposes of this Section 8.2(f), the term
         "threatened imposition" shall mean a formal or informal expression of
         intent by any Governmental Authority.  For purposes of this Section
         8.2(f), the term "pay" shall include, without limitation, any
         imputation of revenues or reduction of revenues, and the term "paying"
         and "payment" shall have corresponding meanings.  In order for Enron
         to assert that the condition set forth in this Section 8.2(f) has not
         been satisfied as a result of any action by a Governmental Authority
         (including without limitation a Final Order of the OPUC), Enron must
         give written notice to PGC to such effect no later than five business
         days after the date of the receipt by Enron of notice that such
         Governmental Authority has taken such action.

         16.     Section 9.1(b) of the Agreement is hereby amended to read in
its entirety as follows:

                 (b)      by Enron or PGC, by written notice to the other, if
         the Effective Time shall not have occurred on or before the first
         anniversary of the date hereof (the "Termination Date"); provided,
         however, that either party may extend the Termination Date for an
         additional six months (or three months if the condition set forth in
         Section 8.2(f) has been satisfied but the condition set forth in
         Section 8.1(a) has not been satisfied) from such anniversary if (i)
         all the conditions to consummation of the Mergers set forth in Article
         VIII hereof have either been satisfied or are then capable of being
         satisfied by such date, other than the conditions set forth in
         Sections 8.1(a) and/or 8.2(f) and (ii) such party believes that there
         is a reasonable probability that such condition will be satisfied by
         or before such extended Termination Date; and provided further, that
         the right to terminate this Agreement under this Section 9.1(b) shall
         not be available to any party whose failure to fulfill any





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         obligation under this Agreement has been the cause of, or resulted in,
         the failure of the Effective Time to occur on or before the
         termination date;

         17.     Section 9.1(c) of the Agreement is hereby amended to read in
its entirety as follows:

                 (c)      by Enron or PGC, by written notice to the other
         party, if (i) the Enron Shareholders' Approval shall not have been
         obtained at the Enron Special Meeting, including any adjournments
         thereof, (ii) the PGC Shareholders' Approval shall not have been
         obtained at the PGC Special Meeting, including any adjournments
         thereof or (iii) the Supplemental PGC Shareholders' Approval shall not
         have been obtained at the Supplemental PGC Shareholders' Meeting,
         including any adjournments thereof

         18.     Section 9.1 of the Agreement is hereby amended by adding a new
paragraph (n), which shall read as follows:

                 (n)      by Enron, by written notice to PGC, if the OPUC
         issues an order (regardless of whether such order has become a Final
         Order) that disapproves the Mergers or that approves the Mergers in a
         manner that does not satisfy the condition set forth in Section
         8.2(f).

         19.     Except as expressly set forth herein, the terms and provisions
of the Agreement are hereby ratified and confirmed.

         20.     This Amendment may be executed in one or more counterparts,
each of which shall be deemed to be an original, but all of which shall
constitute one and the same agreement.





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                          IN WITNESS WHEREOF, Enron, PGC and the Company have
         caused this Amendment to be signed by their respective officers
         thereunto duly authorized as of the date first above written.

                                ENRON CORP.
                                
                                
                                By: /s/ J. CLIFFORD BAXTER 
                                   --------------------------------------------
                                   J. Clifford Baxter
                                   Senior Vice President, Corporate Development
                                
                                PORTLAND GENERAL CORPORATION
                                
                                
                                By: /s/ JOSEPH M. HIRKO
                                   --------------------------------------------
                                   Joseph M. Hirko
                                   Senior Vice President and
                                    Chief Financial Officer
                                
                                ENRON OREGON CORP.
                                
                                
                                By: /s/ EDMUND P. SEGNER, III
                                   --------------------------------------------
                                   Edmund P. Segner, III
                                   President





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