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                                                                     EXHIBIT 3.A

                                    RESTATED

                          CERTIFICATE OF INCORPORATION

                                       OF

                         TENNESSEE GAS PIPELINE COMPANY


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

         Tennessee Gas Pipeline Company, a corporation organized and existing
under the laws of the State of Delaware, hereby certifies as follows:

         1. The name of the corporation is Tennessee Gas Pipeline Company (the
"Corporation"). The Corporation was originally incorporated under the name
Tennessee Gas Transmission Company. The original certificate of incorporation
was filed with the Secretary of State of the State of Delaware on June 9, 1947.

         2. This Restated Certificate of Incorporation restates and further
amends the Certificate of Incorporation of the Corporation and has been adopted
and approved in accordance with Sections 242 and 245 of the General Corporation
Law of the State of Delaware. Stockholder approval of this Restated Certificate
of Incorporation was given by unanimous written consent of the stockholders of
the Corporation in accordance with Section 228 of the General Corporation Law of
the State of Delaware.

         3. The text of the Certificate of Incorporation, as heretofore amended,
is hereby amended and restated to read in its entirety as follows:

         FIRST: The name of the corporation is Tennessee Gas Pipeline Company.

         SECOND: The address of the Corporation's registered office in the State
of Delaware is Corporation Trust Center, 1209 Orange Street, City of Wilmington,
New Castle County, Delaware 19801, and the name of its registered agent at the
above address is The Corporation Trust 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 the State of Delaware.






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         FOURTH: The total number of shares of stock the corporation shall have
authority to issue is three hundred (300) shares of common stock with a par
value of five dollars ($5.00) per share.

         Shares of stock of this corporation whether with or without par value,
of any class or classes hereby or hereafter authorized, may be issued by this
corporation from time to time for such consideration permitted by law as may be
fixed from time to time by the Board of Directors.

         FIFTH: Unless required by the By-laws, the election of the Board of
Directors need not be by written ballot.

         SIXTH: The Board of Directors of this corporation is expressly
authorized to make, alter, or repeal the By-laws of the corporation, but the
stockholders may make additional by-laws and may alter or repeal any By-law
whether or not adopted by them.

         SEVENTH: 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, for any act or omission, except that a director may be
liable (i) for breach of the director's duty of loyalty to the corporation or
its stockholders, (ii) for acts or omissions not in good faith or that involve
intentional misconduct or a knowing violation of law, (iii) under Section 174 of
the General Corporation Law of the State of Delaware, or (iv) for any
transaction from which the director derived an improper personal benefit. If the
General Corporation Law of the State of Delaware is amended to authorize
corporate action further eliminating or limiting the personal liability of
directors, then the liability of the directors shall be eliminated or limited to
the fullest extent permitted by the General Corporation Law of the State of
Delaware, as so amended. The elimination and limitation of liability provided
herein shall continue after a director has ceased to occupy such position as to
acts or omissions occurring during such director's term or terms of office. Any
amendment, repeal or modification of this Article Seventh shall not adversely
affect any right of protection of a director of the Corporation existing at the
time of such repeal or modification.

         IN WITNESS WHEREOF, Tennessee Gas Pipeline Company has caused this
Restated Certificate of Incorporation to be signed by a duly authorized officer
this 11th day of May 1999.

                                        Tennessee Gas Pipeline Company


                                        By:  /s/ Jeffrey I. Beason
                                           -------------------------------------
                                               Jeffrey I. Beason
                                           Vice President and Controller


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