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                                                                EXHIBIT 10.16(i)

                  SECOND AMENDMENT TO TAX ALLOCATION AGREEMENT

WHERAS, PDV America, Inc. ("PDV America"), a corporation organized and existing
under the laws of the state of Delaware, VPHI Midwest, Inc. ("VPHI"), a
corporation organized and existing under the laws of the state of Delaware,
CITGO Petroleum Corporation ("CITGO"), a corporation organized and existing
under the laws of the state of Delaware and PDV USA, Inc. ("PDV USA"), a
corporation organized and existing under the laws of the state of Delaware have
entered into a Tax Allocation Agreement (the "Agreement") dated June 24, 1993
for the purposes of allocating the consolidated federal income tax liability of
the PDV America Group (as defined in the Agreement);

WHEREAS, PDV Holding, Inc. ("PDV Holding"), a corporation organized and existing
under the laws of the state of Delaware, became, effective January 1, 1997, the
common parent corporation of the PDV America group in a transaction that is
treated as a "reverse acquisition" within the meaning of Treasury Regulation
Section 1.1502-75(d)(3);

WHEREAS, PDV Chalmette, Inc. ("PDV Chalmette"), a corporation organized and
existing under the laws of the state of Delaware, became, effective October 17,
1997, a member of the affiliated group of corporations, as defined in Section
1504(a) of the Code (as defined in the Agreement), of which PDV Holding is the
common parent;

WHEREAS, PDV Sweeny, Inc. ("PDV Sweeny"), a corporation organized and existing
under the laws of the state of Delaware, became, effective August 21, 1998, a
member of the affiliated group of corporations, as defined in Section 1504(a) of
the Code (as defined in the Agreement), of which PDV Holding is the common
parent;

WHEREAS, PDV Texas, Inc. ("PDV Texas"), a corporation organized and existing
under the laws of the state of Delaware, became, effective August 21, 1998, a
member of the affiliated group of corporations, as defined in Section 1504(a) of
the Code (as defined in the Agreement), of which PDV Holding is the common
parent;

WHEREAS, Section 12 of the Agreement (as amended by First Amendment to Tax
Allocation Agreement), Survival of the Group, anticipates a reverse acquisition
and the insertion of a new common parent corporation and provides therefore for
the continuation of the Agreement with the new common parent assuming all the
benefits and responsibilities of PDV America, the original common parent; and,

WHEREAS, the parties to the Agreement desire to revoke certain provisions of the
First Amendment to Tax Allocation Agreement effective January 1, 1997.

NOW THEREFORE, in consideration of the mutual covenants and promises contained
herein, and for other good and valuable consideration the receipt and
sufficiency of which are hereby acknowledged, the parties hereto agree as
follows:
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      1.    Section 12 of the Agreement (as amended by First Amendment to Tax
            Allocation Agreement), Survival of the Group, is hereby invoked
            effective as of January 1, 1997 with PDV Holding becoming the common
            parent and, therefore, PDV Holding is hereby substituted for PDV
            America wherever it appears in the Agreement. PDV Holding will
            receive all the benefits and assume all the liabilities that PDV
            America, as common parent, would have received or borne under the
            Agreement, had there been no change in the common parent of the PDV
            America Group. As common parent, PDV Holding hereby agrees to be
            bound by all the terms and conditions of the Agreement.

      2.    PDV America, no longer the common parent of the affiliated group,
            will, effective January 1, 1997, become a member under the Agreement
            as that term is defined in Section 1(a) of the Agreement. As a
            member, PDV America hereby agrees to be bound by all the terms and
            conditions of the Agreement.

      3.    PDV Chalmette will, effective October 17, 1997, become a member
            under the Agreement as that term is defined in Section 1(a) of the
            Agreement. As a member, PDV Chalmette hereby agrees to be bound by
            all the terms and conditions of the Agreement.

      4.    PDV Sweeny will, effective August 21, 1998, become a member under
            the Agreement as that term is defined in Section 1(a) of the
            Agreement. As a member, PDV Sweeny hereby agrees to be bound by all
            the terms and conditions of the Agreement.

      5.    PDV Texas will, effective August 21, 1998, become a member under the
            Agreement as that term is defined in Section 1(a) of the Agreement.
            As a member, PDV Texas hereby agrees to be bound by all the terms
            and conditions of the Agreement.

      6.    The affiliated group of corporations consisting of PDV Holding, PDV
            Chalmette, PDV Sweeny, PDV Texas, PDV America, VPHI, PDV USA and
            CITGO will hereafter be referred to as the PDV Holding Group for all
            purposes of the Agreement.

      7.    Sections 8(a) and (b) of the Agreement (as amended by First
            Amendment to Tax Allocation Agreement) are hereby revoked effective
            January 1, 1997. Therefore, no reclassification entries (as required
            by Section 8(a) and (b)) will be made for any and all tax years
            subsequent to the 1996 tax year.

      8.    The reclassifications previously recorded between CITGO and PDV
            America for those years in which PDV America was the common parent
            (i.e., tax years 1992 through 1996) will remain as recorded until
            required to be reversed as
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            described in Section 8(c) of the Agreement (as amended by First
            Amendment to Tax Allocation Agreement).

      9.    The non-cash contribution recorded in December 1998 related to the
            1997 tax year will be reversed, consistent with the revocation of
            Sections 8 (a) and (b) as discussed above.

      10.   The non-cash dividend recorded in December 1999 related to the 1998
            tax year will be reversed, consistent with the revocation of
            Sections 8 (a) and (b) as discussed above.

IN WITNESS WHEREOF, the parties duly execute this amendment as of the date first
written above.

                                                  PDV Holding, Inc.

                                                  By: /s/ CARLOS JORDA
                                                  ------------------------------


                                                  PDV Chalmette, Inc.

                                                  By: /s/ ALEXANDER CARDENAS
                                                  ------------------------------


                                                  PDV Sweeny, Inc.

                                                  By: /s/ JULIAN FLESZCZYNSKI
                                                  ------------------------------


                                                  PDV Texas, Inc.

                                                  By: /s/ LUIS R. CENTENO
                                                  ------------------------------


                                                  PDV America, Inc.

                                                  By: /s/ LUIS R. CENTENO
                                                  ------------------------------


                                                  VPHI Midwest, Inc.

                                                  By: /s/ JOSE I. MORENO
                                                  ------------------------------


                                                  PDV USA, Inc.

                                                  By: /s/ JOSE I. MORENO
                                                  ------------------------------

                                                  CITGO Petroleum Corporation

                                                  By: /s/ D. JEANNE STURGES
                                                  ------------------------------