Exhibit 3.6

                         CERTIFICATE OF INCORPORATION

                                      OF

                               PAA FINANCE CORP.


     FIRST:  The name of the corporation is PAA Finance Corp.

     SECOND:  The address of its registered office in the State of Delaware is
2711 Centerville Road, Wilmington, Delaware 19808, County of New Castle.  The
name of its registered agent at such address is Corporation Service Company.

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

     FOURTH:  The total number of shares of all classes of stock which the
corporation shall have authority to issue is One Thousand (1,000) shares of
Common Stock of the par value of $0.01 per share.

     FIFTH:  The name of the incorporator is Heather G. Hardwick and her mailing
address is c/o Vinson & Elkins L.L.P., 2300 First City Tower, 1001 Fannin,
Houston, Texas 77002-6720.

     SIXTH:  The names and mailing addresses of the directors, who shall serve
until the first annual meeting of stockholders or until successors are elected
and qualified, are as follows:



     Name                                    Address
     ----                                    -------
                                          
     Greg L. Armstrong                       500 Dallas Street, Suite 700
                                             Houston, Texas 77002
     Harry N. Pefanis                        500 Dallas Street, Suite 700
                                             Houston, Texas 77002
     Phillip D. Kramer                       500 Dallas Street, Suite 700
                                             Houston, Texas 77002


     The number of directors of the corporation shall be as specified in, or
determined in the manner provided in, the bylaws.  Election of directors need
not be by written ballot.


     SEVENTH:  In furtherance of, and not in limitation of, the powers conferred
by statute, the Board of Directors is expressly authorized to adopt, amend or
repeal the bylaws of the corporation.

     EIGHTH:  Whenever a compromise or arrangement is proposed between this
corporation and its creditors or any class of them and/or between this
corporation and its stockholders or any class of them, any court of equitable
jurisdiction within the State of Delaware may, on the application in a summary
way of this corporation or of any creditor or stockholder thereof or on the
application of any receiver or receivers appointed for this corporation under
the provisions of Section 291 of Title 8 of the Delaware Code or on the
application of trustees in dissolution or of any receiver or receivers appointed
for this corporation under the provisions of Section 279 of Title 8 of the
Delaware Code order a meeting of the creditors or class of creditors, and/or of
the stockholders or class of stockholders of this corporation, as the case may
be, to be summoned in such manner as the said court directs.  If a majority in
number representing three-fourths in value of the creditors or class of
creditors, and/or of the stockholders or class of stockholders of this
corporation, as the case may be, agree to any compromise or arrangement and to
any reorganization of this corporation as a consequence of such compromise or
arrangement, the said compromise or arrangement and the said reorganization
shall, if sanctioned by the court to which the said application has been made,
be binding on all the creditors or class of creditors, and/or on all the
stockholders or class of stockholders, of this corporation, as the case may be,
and also on this corporation.

     NINTH:  No director of the Corporation shall be liable to the Corporation
or its stockholders for monetary damages for breach of fiduciary duty as a
director, except for liability (i) for any breach of the director's duty of
loyalty to the Corporation or its stockholders, (ii) for acts or omissions not
in good faith or which involve intentional misconduct or a knowing violation of
law, (iii) under

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Section 174 of the Delaware General Corporation Law, or (iv) for any transaction
from which the director derived an improper personal benefit.

     TENTH:  The corporation shall have the right, subject to any express
provisions or restrictions contained in the certificate of incorporation or
bylaws of the corporation, from time to time, to amend the certificate of
incorporation or any provision thereof in any manner now or hereafter provided
by law, and all rights and powers of any kind conferred upon a director or
stockholder of the corporation by the certificate of incorporation or any
amendment thereof are subject to such right of the corporation.

                                 [END OF PAGE]

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     I, the undersigned, being the incorporator hereinbefore named, for the
purpose of forming a corporation pursuant to the General Corporation Law of the
State of Delaware, do make this certificate, hereby declaring that this is my
act and deed and that the facts herein stated are true, and accordingly have
hereunto set my hand this 12/th/ day of February, 2001.

                                    /s/ Heather G. Hardwick
                                    -----------------------
                                    Heather G. Hardwick, Incorporator

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