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                                                                  Exhibit 10(xx)


                         TRINIDAD U.S. PLEDGE AGREEMENT
                 (PLEDGE OF INTEREST IN YORK T&T HOLDINGS, INC.)


                  This TRINIDAD U.S. PLEDGE AGREEMENT (this "Pledge Agreement"),
dated as of August 4, 1998, is entered into by YORK RESEARCH CORPORATION, a
Delaware corporation (the "Pledgor"), in favor of THE BANK OF NEW YORK, a New
York banking corporation, as trustee under that certain Indenture described in
the recitals below, and as collateral agent under the Intercreditor Agreement
for the benefit of the Secured Parties (in such capacity, the "Collateral
Agent").

                              W I T N E S S E T H:

                  WHEREAS, the Pledgor owns a one hundred percent (100%) equity
interest in York T&T Holdings, Inc., a Delaware corporation (the "Company");

                  WHEREAS, York Power Funding (Cayman) Limited (the "Funding
Company") is a limited liability company organized under the laws of the Cayman
Islands for the sole purpose of issuing the Securities pursuant to the Indenture
and making loans to the Project Borrowers from the proceeds of such issuance;

                  WHEREAS, the Funding Company has on the date hereof issued and
sold Securities in the principal amount of $160 million;

                  WHEREAS, the principal and interest payments on the Securities
will be partially serviced by repayment of a loan made by the Funding Company to
the Trinidad Project Borrower and guaranteed by the Trinidad Guarantor, subject
to the conditions set forth in the Finance Documents;

                  WHEREAS, the Funding Company will loan $100 million of the
proceeds of issuance of the Securities to the Trinidad Project Borrower, which
will be contributed by the Trinidad Project Borrower to the Trinidad Guarantor
and will be loaned by the Trinidad Guarantor to the Trinidad Obligor pursuant to
the Trinidad Loan Agreement; and

                  WHEREAS, the Pledgor anticipates benefiting directly and
indirectly from the making of the Trinidad Project Loan by the Funding Company
to the Trinidad Project Borrower pursuant to the Trinidad Project Loan Agreement
and is, therefore, willing to enter into this Pledge Agreement in accordance
with the terms hereof.

                  NOW, THEREFORE, in consideration of the mutual covenants
contained herein, and for other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, and in order to induce the Funding
Company to enter into the Trinidad Project Loan Agreement, the parties hereto
hereby agree as follows:

                  1.  DEFINITIONS.

                           (a) Unless otherwise defined herein, all capitalized
         terms shall have the meanings set forth in Appendix A to the Indenture,
         which Appendix A is hereby incorporated by reference. All references to
         sections, schedules and exhibits in or to this Pledge Agreement are to



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         sections, schedules and exhibits in or to this Pledge Agreement, unless
         otherwise specified. The words "hereof," "herein" and "hereunder" and
         words of similar import when used in this Pledge Agreement shall refer
         to this Pledge Agreement as a whole and not to any particular provision
         of this Pledge Agreement. For purposes of this Pledge Agreement, all
         other terms used herein and not otherwise defined herein which are
         defined in Article 9 of the Uniform Commercial Code (as the same may be
         in effect in the State of New York or any other applicable
         jurisdiction, the "UCC"), shall have their respective meanings as
         therein defined.

                           (b) The following terms used herein shall have the
         following meanings:

                           "Collateral" has the meaning set forth in SECTION 2.1
         herein.

                           "Company" means York T&T Holdings, Inc., a Delaware
         corporation.

                           "Exculpated Parties" has the meaning set forth in
         SECTION 21.1 herein.

                           "Obligations" has the meaning set forth in SECTION
         2.2 herein.

                           "Pledgor" means York Research Corporation, a Delaware
         corporation.

                           "Security Interest" has the meaning set forth in
         SECTION 2.1 herein.

                           "UCC" means Article 9 of the Uniform Commercial Code,
         as the same may be in effect in the State of New York or any other
         applicable jurisdictions.

                  2.  GRANT OF SECURITY INTEREST.

                           2.1. COLLATERAL. As security for the prompt and
complete payment and performance when due (whether at stated maturity, by
acceleration or otherwise) of any and all of the Obligations (as defined below)
now existing or hereafter arising, and howsoever evidenced, the Pledgor hereby
collaterally assigns, conveys, mortgages, pledges, hypothecates and transfers to
the Collateral Agent, and grants and creates a lien on and first priority
security interest (the "Security Interest") in favor of the Collateral Agent,
for the equal and ratable benefit of the Secured Parties, in all right, title
and interest of the Pledgor in, to and under the following, whether now existing
or hereafter acquired (collectively, the "Collateral"):

                           (a) its seventy-nine percent (79%) equity interest in
         the Company, including, without limitation, to the extent assignable or
         transferable, all of its right, title and interest as a shareholder to
         participate in the operation or management and control of the Company;

                           (b) all present and future rights of the Pledgor to
         receive any payment of money or other distribution or payment arising
         out of or in connection with its equity interest in the Company; and

                           (c) to the extent not otherwise included, all
         proceeds, products and accessions of and to any and all of the
         foregoing, including, without limitation, "proceeds" as defined in
         Section 9-306(1) of the Code, including whatever is received upon any
         sale, exchange, collection or other disposition of any of the
         Collateral, and any property into which any of the Collateral is
         converted, whether cash or non-cash proceeds, and any and all other
         amounts paid or payable under or in connection with any of the
         Collateral.
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                           2.2. OBLIGATIONS. This Pledge Agreement secures, in
accordance with the provisions hereof, the following obligations, now existing
or hereafter arising (collectively, the "Obligations"):

                           (a) payment and performance of the Company's
         obligations, indebtedness, covenants and agreements of the Company
         under any of the Finance Documents to which it is a party, including,
         without limitation, this Pledge Agreement and any amendments or
         supplements thereto, extensions or renewals thereof or replacements
         therefor; and

                           (b) performance of every obligation, covenant and
         agreement of the Company contained in any agreement now or hereafter
         executed by the Company which recites that the obligations thereunder
         are secured by this Pledge Agreement; in each case whether direct or
         indirect, joint or several, absolute or contingent, liquidated or
         unliquidated, now or hereafter existing, renewed or restructured,
         reinstated, created or incurred, and, including, without limitation,
         all indebtedness of the Pledgor under any instrument now or hereafter
         evidencing or securing any of the foregoing.

                  3. REPRESENTATIONS AND WARRANTIES. The Pledgor hereby
represents and warrants as follows:

                           3.1. ORGANIZATION AND EXISTENCE. The Company is a
corporation in which the Pledgor owns a one hundred percent (100%) equity
interest. The Pledgor is a corporation duly organized, validly existing and in
good standing under the laws of the State of Delaware. The Pledgor is duly
qualified to do business and is in good standing in each other jurisdiction in
which the character of the properties owned or leased by it or in which the
transaction of its business as presently conducted or proposed to be conducted
makes such qualification necessary or desirable, except when the failure to be
so qualified would not have a Material Adverse Effect. The Pledgor has full
power and authority to own its property and to carry on its business as now
being conducted and as proposed to be conducted.

                           3.2. AUTHORITY, ENFORCEABILITY. The Pledgor has full
power and authority to enter into and perform this Pledge Agreement and the
entering into and performance of such agreement by the Pledgor has been duly
authorized by all proper and necessary action. Such agreement, when executed and
delivered by the Pledgor and any other party thereto, will constitute the legal,
valid and binding obligation of the Pledgor, enforceable in accordance with its
respective terms, except as enforceability may be limited by bankruptcy or other
laws involving auditors rights or general principles of equity.

                           3.3. NO CONFLICT. Neither the execution, delivery and
performance of this Pledge Agreement nor of any other Transaction Document to
which the Pledgor is a party nor the consummation of any of the transactions
contemplated hereby or thereby (a) contravenes or violates any provision of any
Applicable Law to which the Pledgor or any of its assets is subject, (b)
conflicts with or is inconsistent with, will result in a breach of any of the
terms, covenants, conditions or provisions of, constitutes a default under, or
results in the acceleration of Indebtedness evidenced by, any agreement or
instrument to which the Pledgor is a party or by which it or any of its
properties or assets is bound or to which it may be subject, except, in the case
of this clause (b), any such conflict, violation, breach, default or
acceleration which could not reasonably be expected to result in a Material
Adverse Effect or (c) results in the creation or imposition of (or the
obligations to create or impose) any Lien upon any of the properties or assets
of the Pledgor.

                           3.4. TITLE; NO OTHER LIENS. The Pledgor is the legal
and beneficial owner of the Collateral in existence on the date hereof and will
be the sole owner of the Collateral hereafter acquired, free and clear of any
and all Liens or claims of others, and the Pledgor has full power and authority
to

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grant the liens and security interests in and to the Collateral hereunder.
Except with respect to the Secured Parties and as required under this Pledge
Agreement, no security agreement, financing statement or other public notice
with respect to all or any part of the Collateral is on file or of record in any
public office, and no lien or security interest on or in the Collateral has been
registered in the registration book maintained by the Company in which all
equity interests of the Company are recorded, except such as may have been filed
in favor of Collateral Agent for the benefit of the Secured Parties pursuant to
this Pledge Agreement.

                           3.5. PERFECTION; REGISTRATION OF LIEN. Financing
statements or other appropriate instruments have been filed or deposited for
filing pursuant to the Code in such public offices as may be necessary to
perfect any Security Interest granted or purported to be granted hereby to the
extent any such Security Interest may be perfected by the filing of a financing
statement. All other action by the Pledgor and, to the Pledgor's knowledge, by
any other Person necessary or desirable to perfect the Security Interest in each
item of the Collateral has been duly taken. Subject to the requirements
contained in the Code with respect to the filing of continuation statements,
this Pledge Agreement constitutes a valid and continuing Lien on and perfected
Security Interest in the Collateral in favor of the Collateral Agent for the
equal and ratable benefit of the Secured Parties, superior and prior to the
rights of all Persons, whether the Collateral subject to the Security Interest
is now owned by the Pledgor or is hereafter acquired.

                           3.6. NO DEFAULT. The Pledgor is not in default in the
performance, observance or fulfillment of any of the material obligations,
covenants or conditions applicable to the Pledgor contained in any Finance
Document to which it is a party.

                           3.7. CHIEF EXECUTIVE OFFICE AND PRINCIPAL PLACE OF
BUSINESS. The Pledgor's chief executive office and principal place of business
and the place where the Pledgor's records concerning the Collateral are kept is
York Research Corporation, 280 Park Avenue, Suite 2700W, New York, New York
10017.

                  4. COVENANTS AND AGREEMENTS. The Pledgor hereby covenants and
agrees that the Pledgor shall faithfully observe and fulfill, and shall cause to
be observed and fulfilled, each and all of the following covenants until the
Debt Termination Date:

                           4.1. FURTHER ASSURANCES. The Pledgor shall, from time
to time at the Trinidad Guarantor's expense, and upon request by the Collateral
Agent on behalf of the Secured Parties, promptly execute and deliver all further
instruments and documents, and take all further action that may be reasonably
necessary or advisable, or that the Collateral Agent reasonably determines may
be necessary, in order to perfect and protect the Security Interest granted or
purported to be granted hereby or to enable the Collateral Agent to exercise and
enforce its rights and remedies hereunder with respect to the Collateral.

                           4.2. CERTIFICATED INTEREST. If the Pledgor shall
become entitled to receive or shall receive any certificate, instrument, option
or rights, whether as an addition to, in substitution of, or in exchange for the
Collateral or any part thereof, or otherwise, the Pledgor shall accept any such
certificate, instrument, option or rights as the Collateral Agent's agent, shall
hold them in trust for the Collateral Agent, and shall deliver them forthwith to
the Collateral Agent in the exact form received, with the Pledgor's endorsement
when necessary, or accompanied by duly executed instruments of transfer or
assignment in blank or, if requested by the Collateral Agent, an additional
pledge agreement or security agreement executed and delivered by the Pledgor,
all in form and substance satisfactory to the Collateral Agent, to be held by
the Collateral Agent, subject to the terms hereof, as further Collateral for the
Obligations.

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                           4.3. CHANGE IN LOCATION, NAME, ETC. The Pledgor may
change the location of its chief executive office, principal place of business
or the office where such records are kept to another location in the United
States after giving the Collateral Agent thirty (30) days' advance written
notice of such change. Without the prior written consent of the Collateral
Agent, the Pledgor shall not adopt any trade name or fictitious business name.

                           4.4. LIMITATION ON LIENS ON THE COLLATERAL. The
Pledgor shall not create, incur or permit to exist, shall defend the Collateral
now owned or hereafter acquired by it against, and shall take such other action
as is necessary to remove, any Lien or claim on or to the Collateral, and shall
defend the right, title and interest of the Collateral Agent in and to any of
the Collateral against the claims and demands of all Persons whomsoever.

                           4.5. BANKRUPTCY FILING, ETC. To the maximum extent
permitted by law, the Pledgor shall not authorize or permit the Company (a) to
commence a voluntary case or other proceeding seeking liquidation,
reorganization or other relief with respect to the Company or the Company's
debts under any bankruptcy, insolvency or other similar law now or hereafter in
effect or seeking the appointment of a trustee, receiver, liquidator, custodian
or other similar official of the Company or any substantial part of the
Company's property, (b) to consent to any such relief or to the appointment of
or taking possession by any such official in an involuntary case or other
proceeding commenced against the Company or (c) to make a general assignment for
the benefit of the Company's creditors. Neither the Pledgor nor any of its
Affiliates shall commence or join with any other Person (other than the Secured
Parties) in commencing any proceeding against the Company under any bankruptcy,
reorganization, liquidation or insolvency law or statute now or hereafter in
effect in any jurisdiction.

                           4.6. OBLIGATIONS. The Pledgor acknowledges and agrees
that its rights to receive any payments from the Company, or arising out of or
in connection with the Pledgor's interests in the Company, shall be payable by
the Company only from funds available to the Company upon distributions pursuant
to the Trinidad Depositary Agreement or any other provision of the Indenture
expressly providing for distribution, payment or release of funds to the
Company, and only so long as such distribution, payment or release is made in
accordance with the Trinidad Depositary Agreement and the Indenture. The Pledgor
also agrees that any distributions made by the Company to the Pledgor that do
not comply with the Trinidad Depositary Agreement and the Indenture shall be
restored to the Company by the Pledgor by deposit into an account designated by
the Collateral Agent, promptly upon demand by the Collateral Agent or the
Company or upon the Pledgor becoming aware of receipt of such non-complying
distribution.

                           4.7. GOVERNMENTAL AUTHORITY REQUIREMENT. The Pledgor
shall not take or omit to take (or suffer such taking or omission of) any action
(unless ordered to do so by a competent Governmental Authority having
jurisdiction) in respect of the Pledgor or the Company and their respective
businesses if, as a consequence directly or indirectly of such action or
omission, the Company or the Pledgor becomes subject to regulation by any
Governmental Authority as a "public utility," an "electric utility," an
"electric utility holding company," a "public utility company" or a subsidiary
company or affiliate of any of the foregoing under PUHCA, FPA or PURPA, or as a
"holding company" within the meaning of PUHCA.

                           4.8. INDEMNIFICATION. The Pledgor shall defend,
indemnify and hold harmless the Collateral Agent and each of the other Secured
Parties and their officers, directors and employees, from and against any and
all costs, expenses, disbursements, liabilities, obligations, losses, damages,
injunctions, judgments, suits, actions, causes of action, fines, penalties,
claims and demands, of every kind or nature (including, without limitation,
reasonable attorney's fees and expenses) which are occasioned by or result from
any (a) failure by the Pledgor to perform any of the terms, agreements, or

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covenants to be performed by the Pledgor under this Pledge Agreement and (b)
proceeding or action to enforce brought by the Collateral Agent pursuant to this
Pledge Agreement or which arise out of any such agreement unless due solely to
the gross negligence or willful misconduct of the Collateral Agent. This
indemnity and any other obligations of the Pledgor under any of the Finance
Documents shall be made only against, and shall be limited to the extent of, the
Collateral pledged hereunder.

                  5. COVENANTS; CASH DIVIDENDS; VOTING RIGHTS. Unless and until
an Event of Default shall have occurred and be continuing, the Pledgor shall be
entitled to (a) receive ordinary cash dividends payable in respect of the
Collateral and (b) exercise (but only in a manner not inconsistent with the
terms hereof and the Finance Documents) the voting power with respect to the
Collateral; PROVIDED, that no vote shall be cast or consent, waiver or
ratification given or action taken which would impair the Collateral or be
inconsistent with or violate any provision of this Pledge Agreement or any of
the Finance Documents. After the occurrence and during the continuance of any
Event of Default, (a) the Pledgor shall not be entitled to receive any dividends
or distributions in respect of the Collateral (whether payable in cash or in
other property and whether ordinary dividends or liquidating or other dividends
or distributions) and if such dividend or distribution is received by the
Pledgor, the same shall be held in trust and promptly delivered to the
Collateral Agent, accompanied by undated, duly executed stock powers endorsed by
the Pledgor in blank or such other instruments of assignment as the Collateral
Agent may request, to be held by it as additional Collateral hereunder and (b)
the Collateral Agent may, at its option, by written notice to the Pledgor, elect
to exercise the voting power with respect to the Collateral.

                  6. PLEDGOR'S OBLIGATIONS UPON EVENT OF DEFAULT. If an Event of
Default under the Trinidad Project Loan Agreement or the Trinidad Guarantee
shall occur and be continuing (a) all payments received by the Pledgor under or
in connection with any of the Collateral shall be held by the Pledgor in trust
for the Collateral Agent, shall be segregated from other funds of the Pledgor
and shall, forthwith upon receipt by the Pledgor, be turned over to the
Collateral Agent or its designee in the same form as received by the Pledgor
(duly endorsed by the Pledgor to the Collateral Agent, if requested), and (b)
any and all such payments so received by the Collateral Agent or its designee
(whether from the Pledgor or otherwise) may, in the sole discretion of the
Collateral Agent or its designee, be held by the Collateral Agent or such
designee as collateral security for, and/or then or at any time thereafter be
applied, subject only to the relevant provisions of the Intercreditor Agreement
and the Trinidad Depositary Agreement or as otherwise may be required by
Applicable Law, in whole or in part by the Collateral Agent or its designee in
the manner specified in SECTION 8.

                  7. REMEDIES; RIGHTS UPON EVENT OF DEFAULT. Upon the occurrence
and during the continuance of an Event of Default under the Trinidad Project
Loan Agreement or the Trinidad Guarantee, the Collateral Agent, for the equal
and ratable benefit of and on behalf of the Secured Parties, may, subject to the
provisions of the Intercreditor Agreement and the other Finance Documents, do
one or more of the following:

                           7.1. declare, without presentment, demand, protest or
notice of any kind, all of which the Pledgor hereby expressly waives, the entire
amount of the Obligations to be immediately due and payable, whereupon all of
such Obligations declared due and payable shall be and become immediately due
and payable; provided, however, if, with respect to the Trinidad Guarantor, an
Event of Default occurs pursuant to Section 5.1(f) of the Trinidad Project Loan
Agreement, then the acceleration provided for in this Section 7.1 shall be
deemed to have been made upon the occurrence of such Event of Default without
declaration or any other action by the Collateral Agent;

                           7.2. upon notice to the Pledgor, which notice need
not be in writing, make such payments and do such acts as the Collateral Agent
may deem necessary to protect, perfect or continue the perfection of the Secured
Parties' Security Interest in the Collateral, including without limitation,
paying,

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purchasing, contesting or compromising any Lien which is, or purports to
be, prior to or superior to the Security Interest granted hereunder, and
commencing, appearing or otherwise participating in or controlling any action or
proceeding purporting to affect the Secured Parties' Security Interest in or
ownership of the Collateral;

                           7.3. foreclose on the Collateral as herein provided
or in any manner permitted by law and exercise any and all of the rights and
remedies conferred upon the Secured Parties by the Security Documents either
concurrently or in such order as the Collateral Agent may determine without
affecting the rights or remedies to which the Secured Parties may be entitled
under any Security Document. The Pledgor hereby waives, to the extent permitted
by Applicable Law, notice and judicial hearing in connection with the Collateral
Agent's taking possession or collection, recovery, receipt, appropriation,
repossession, retention, set-off, sale, leasing, conveyance, assignment,
transfer or other disposition of or realization upon any or all of the
Collateral, including, without limitation, any and all prior notice and hearing
for any prejudgment remedy or remedies and any such right which the Pledgor
would otherwise have under the constitution or any statute or other law of the
United States of America or of any state;

                           7.4. without notice, except as specified below, sell
the Collateral, or any part thereof, in one or more parcels at public or private
sale, at any of the Collateral Agent's offices or elsewhere, at such time or
times, for cash, on credit or for future delivery, and at a commercially
reasonable price or prices and on other commercially reasonable terms. The
Pledgor agrees that, to the extent notice of sale shall be required by law, at
least ten (10) days' notice to the Pledgor of the time and the place of any
public sale or the time after which any private sale is to be made shall
constitute reasonable notification. At any sale of the Collateral, if permitted
by law, the Collateral Agent may bid (which bid may be, in whole or in part, in
the form of cancellation of indebtedness) for the purchase of the Collateral or
any portion thereof for the account of the Collateral Agent on behalf of the
Secured Parties. The Collateral Agent shall not be obligated to make any sale of
the Collateral regardless of notice of sale having been given. The Collateral
Agent may adjourn any public or private sale from time to time by announcement
at the time and place fixed therefor, and such sale may, without further notice,
be made at the time and place to which it was so adjourned. The Collateral Agent
shall incur no liability as a result of the manner of sale of the Collateral, or
any part thereof, at any private sale conducted in a commercially reasonable
manner. The Pledgor hereby waives, to the extent permitted by Applicable Law,
any claims against the Collateral Agent arising by reason of the fact that the
price at which the Collateral, or any part thereof, may have been sold at a
private sale was less than the price which might have been obtained at public
sale or was less than the aggregate amount of the Obligations, even if the
Collateral Agent accepts the first offer received which the Collateral Agent in
good faith deems to be commercially reasonable under the circumstances and does
not offer the Collateral to more than one offeree. To the full extent permitted
by law, the Pledgor shall have the burden of proving that any such sale of the
Collateral was conducted in a commercially unreasonable manner. To the extent
permitted by law, the Pledgor hereby specifically waives all rights of
redemption, stay or appraisal which it has or may have under any law now
existing or hereafter enacted. The Pledgor authorizes the Collateral Agent, at
any time and from time to time, to execute, in connection with a sale of the
Collateral pursuant to the provisions of this Pledge Agreement, any
endorsements, assignments or other instruments of conveyance or transfer with
respect to the Collateral;

                           7.5. upon notice to the Pledgor, register the
Collateral in the name of the Collateral Agent or its nominee as pledgee or
otherwise take such action as the Collateral Agent shall in its sole discretion
deem necessary or desirable with respect to the Collateral, and the Collateral
Agent or its nominee may thereafter, in its sole discretion, without notice,
exercise all voting, consent, managerial and other rights relating to the
Collateral and exercise any and all rights of conversion, exchange, subscription
or any other rights, privileges or options pertaining to the Collateral as if it
were the absolute

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owner thereof, including, without limitation, the right to (a) receive all
permitted distributions, if any, made for the account of the Pledgor and (b)
exchange any and all of the Collateral upon the merger, consolidation,
reorganization, recapitalization or other readjustment of the Company, all
without liability except to account for property actually received by the
Collateral Agent, but the Collateral Agent shall have no duty to exercise any of
the aforesaid rights, privileges or options and shall not be responsible for any
failure to do so or delay in so doing; and

                           7.6. exercise in respect of the Collateral, in
addition to other rights and remedies provided for herein or otherwise available
to it, all the rights and remedies of a secured party after default under the
Code.

                  8. APPLICATION OF PROCEEDS. The net proceeds of any
foreclosure, collection, recovery, receipt, appropriation, realization or sale
of the Collateral shall be applied in the order of priority specified in Section
13 of the Intercreditor Agreement. Any surplus remaining upon the Debt
Termination Date shall be paid to the Pledgor, if it is lawfully entitled to
receive the same or shall be paid to whomsoever a court of competent
jurisdiction may direct.

                  9. SECURITY INTEREST ABSOLUTE. All the rights of the
Collateral Agent and any of the other Secured Parties hereunder and the Security
Interest and all Obligations of the Pledgor hereunder shall be absolute and
unconditional irrespective of:

                           9.1. any lack of validity or enforceability of any of
the Transaction Documents or any other agreement or instrument relating thereto;

                           9.2. any change in the time, manner or place of
payment of, or in any other term of, all or any of the Obligations, or any other
amendment or waiver of or any consent to any departure from any of the
Transaction Documents;

                           9.3. any exchange or release of any Collateral or any
other collateral, or the non-perfection of any of the Security Interest, or any
release or amendment or waiver of or consent to or departure from any guaranty,
for all or any of the Obligations;

                           9.4. to the full extent permitted by law, any other
circumstance that might otherwise constitute a defense available to, or a
discharge of, the Pledgor or any third party pledgor; or

                           9.5. the failure by the Pledgor to fulfill its
Obligations under this Pledge Agreement.


                  10. COLLATERAL AGENT APPOINTED ATTORNEY-IN-FACT.

                           10.1. POWERS. The Pledgor hereby irrevocably
constitutes and appoints the Collateral Agent and any officer or agent thereof,
with full power of substitution, as the Pledgor's true and lawful
attorney-in-fact (which appointment as attorney-in-fact shall be coupled with an
interest), with full authority in the place and stead of the Pledgor and in the
name of the Pledgor or otherwise, from time to time upon the occurrence and
during the continuance of any Event of Default under the Trinidad Project Loan
Agreement or the Trinidad Guarantee in the Collateral Agent's discretion, to
take any action and to execute any and all documents and instruments which the
Collateral Agent may deem necessary or advisable to accomplish the purposes of
this Pledge Agreement, without notice to the Pledgor, including, without
limitation:

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                           (a) to exercise all rights, powers and privileges to
         the same extent the Pledgor shall have been entitled in accordance with
         Applicable Law, including, without limitation, all voting rights of the
         Pledgor as a shareholder of the Company;

                           (b) to receive, endorse and collect all instruments
         made payable to the Pledgor representing any interest payment or other
         distribution in respect of the Collateral or any part thereof and to
         give full discharge for the same and to file any claim or to take any
         other action or proceeding in any court of law or equity or otherwise
         deemed appropriate by the Collateral Agent for the purpose of
         collecting any and all of such dividends, payments or other
         distributions;

                           (c) to pay or discharge taxes and liens levied or
         placed on the Collateral; and

                           (d) (i) to direct any party liable for any payment in
         respect of or arising out of any of the Collateral to make payment of
         any and all moneys due or to become due in connection therewith
         directly to the Collateral Agent or as the Collateral Agent shall
         otherwise direct, (ii) to ask or make demand for, collect, receive
         payment of and receipt for, any and all moneys, claims and other
         amounts due or to become due at any time in respect of or arising out
         of any Collateral, (iii) to commence and prosecute any suits, actions
         or proceedings at law or in equity in any court of competent
         jurisdiction to collect the Collateral or any part thereof and to
         enforce any other right in respect of any Collateral, (iv) to defend
         any suit, action or proceeding brought against the Pledgor with respect
         to any Collateral, (v) to settle, compromise or adjust any suit, action
         or proceeding described in clause (iv) above and, in connection
         therewith, to give such discharges or releases as the Collateral Agent
         acting in good faith may deem appropriate, (vi) generally, to sell,
         transfer, pledge and make any agreement with respect to or otherwise
         deal with any of the Collateral as fully and completely as though the
         Collateral Agent were the absolute owner thereof for all purposes and
         (vii) to do, at the Collateral Agent's option and at the Pledgor's
         expense, at any time, or from time to time, all acts and things which
         the Collateral Agent acting in good faith deems necessary to protect,
         preserve or realize upon the Collateral and the Security Interest
         granted herein and to effect the intent of this Pledge Agreement, all
         as fully and effectively as the Pledgor might do.

                           10.2. OTHER POWERS. The Pledgor further authorizes
the Collateral Agent, at any time and from time to time (a) to execute, in
connection with any sale provided for hereunder, any endorsements, assignments
or other instruments of conveyance or transfer with respect to the Collateral
and (b) to the full extent permitted by Applicable Law, to file one or more
financing or continuation statements, and amendments thereto, relative to all or
any part of the Collateral without the signature of the Pledgor.

                  11. COLLATERAL AGENT MAY PERFORM. Upon the occurrence and
during the continuance of an Event of Default under the Trinidad Project Loan
Agreement or the Trinidad Guarantee, the Collateral Agent, without releasing the
Pledgor from any obligation, covenant or condition hereof, itself may make any
payment or perform, or cause the performance of, any such obligation, covenant,
condition or agreement or any other action in such manner and to such extent as
the Collateral Agent may deem necessary to protect, perfect or continue the
perfection of the Secured Parties' Security Interest in the Collateral. Any
costs or expenses incurred by the Collateral Agent in connection with the
foregoing shall be governed by the Indenture and the Financing Documents and
constitute Obligations secured hereby.

                  12. NO DUTY ON COLLATERAL AGENT'S PART, LIMITATION ON
COLLATERAL AGENT'S OBLIGATIONS.

                           12.1. NO DUTY ON COLLATERAL AGENT'S PART. The powers
conferred on the Collateral Agent hereunder are solely to protect the Collateral
Agent's interests in the Collateral and shall

                                      -9-

<PAGE>

not impose any duty upon it to exercise any such powers. The Collateral Agent
shall be accountable only for amounts that it actually receives as a result of
the exercise of such powers.

                           12.2. LIMITATIONS ON OBLIGATIONS. Without limiting
the effectiveness of SECTION 30 hereof, anything herein to the contrary
notwithstanding, the Pledgor shall remain liable under any Transaction Document
to which it is a party to the extent set forth therein to perform all of its
duties and obligations thereunder, to the same extent as if this Pledge
Agreement had not been executed. The exercise by the Collateral Agent of any of
the rights or remedies hereunder shall not release the Pledgor from any of its
duties or obligations under any Transaction Document to which it is a party. All
of the Collateral is hereby assigned to the Collateral Agent solely as security,
and the Collateral Agent shall have no duty, liability or obligation whatsoever
with respect to any of the Collateral, unless the Collateral Agent so elects in
writing consistent with its rights under this Pledge Agreement.

                  13. REASONABLE CARE. The Collateral Agent shall exercise the
same degree of care hereunder as it exercises in connection with similar
transactions for its own account. The Collateral Agent shall be deemed to have
exercised reasonable care in the custody and preservation of the Collateral in
its possession if the Collateral is accorded treatment substantially equal to
that which the Collateral Agent accords or would accord collateral held by the
Collateral Agent in similar transactions for its own account. Without limiting
the generality of the foregoing and except as otherwise provided by Applicable
Law, the Collateral Agent shall not be required to marshal any Collateral,
including, without limitation, the Collateral subject to the Security Interest
created hereby and any guaranties of the Obligations, or to resort to any item
of Collateral or guaranties in any particular order. All of the Collateral
Agent's rights hereunder and in respect of such Collateral and guaranties shall
be cumulative and in addition to all other rights, however existing or arising.
To the extent that the Pledgor lawfully may, the Pledgor hereby (a) agrees that
it will not invoke any law relating to the marshalling of the Collateral which
might cause delay in or impede the enforcement of the Collateral Agent's rights
under this Pledge Agreement or under any other instrument evidencing any of the
Obligations or under which any of the Obligations is outstanding or by which any
of the Obligations is secured or guaranteed and (b) irrevocably waives the
benefits of all laws and any and all rights to equity of redemption or other
rights of redemption that it may have in equity or at law with respect to the
Collateral.

                  14. ROLE OF COLLATERAL AGENT. The rights, duties, liabilities,
protections, benefits and immunities of the Collateral Agent and its appointment
and replacement hereunder shall be governed by the Intercreditor Agreement or
the Indenture, as applicable.

                  15. WAIVER OF TRIAL BY JURY. WITH REGARD TO THIS PLEDGE
AGREEMENT, EACH OF THE PLEDGOR AND THE COLLATERAL AGENT HEREBY WAIVES THE RIGHTS
TO A TRIAL BY JURY IN ANY ACTION OR PROCEEDING AND FOR ANY COUNTERCLAIM THEREIN.

                  16. NOTICES. All notices, demands, requests and other
communications required or permitted hereunder shall be in writing, and shall be
given and deemed to have been given in accordance with Section 6.1 of the
Trinidad Project Loan Agreement and the information set forth immediately below
shall apply to:

                           If to the Pledgor:
                           York Research Corporation
                           280 Park Avenue, Suite 2700W
                           New York, New York  10017
                           Attention:  Michael Trachtenberg

                                      -10-

<PAGE>

                           If to the Collateral Agent:
                           The Bank of New York
                           101 Barclay Street, Floor 21 West
                           New York, New York  10286
                           Attention:  Corporate Trust Administration--
                             International Finance Unit

                  17. ABSENCE OF FIDUCIARY RELATION. The Collateral Agent
undertakes to perform or to observe only such of its agreements and obligations
as are specifically set forth in this Pledge Agreement, the Intercreditor
Agreement or any other Transaction Document, and no implied agreements,
covenants or obligations with respect to the Pledgor, any Affiliate of the
Pledgor or any other party to any Transaction Document to which the Pledgor is a
party shall be read into this Pledge Agreement against the Collateral Agent or
any of the Secured Parties; neither the Collateral Agent nor any of the Secured
Parties in its and their capacity as such is a fiduciary of and shall not owe or
be deemed to owe any fiduciary duty to the Pledgor, any Affiliate of the Pledgor
or any other party to any Transaction Document to which the Pledgor is a party,
except as otherwise specifically required by law.

                  18. SURVIVAL OF REPRESENTATIONS AND WARRANTIES. All
agreements, representations and warranties made herein shall survive the
execution and delivery of this Pledge Agreement and the other Finance Documents
and repayment of the Obligations, and shall be deemed to be material and to have
been relied upon by the Collateral Agent and any of the other Secured Parties,
regardless of any investigation made by or on behalf of any of the Collateral
Agent and any of the other Secured Parties. Notwithstanding anything in this
Pledge Agreement or implied by law to the contrary, the agreements and
obligations of the Pledgor set forth in SECTION 4.6 shall survive until the Debt
Termination Date or prepayment in full of the Obligations and the termination of
this Pledge Agreement in accordance with SECTION 28 hereof.

                  19. NO WAIVER; CUMULATIVE REMEDIES. By exercising or failing
to exercise any of its rights, options or elections hereunder (without also
expressly waiving the same in writing), the Collateral Agent, on behalf of the
Secured Parties, shall not be deemed to have waived any breach or default on the
part of the Pledgor or to have released the Pledgor from any of its obligations
secured hereby. No failure on the part of the Collateral Agent to exercise, and
no delay in exercising (without also expressly waiving the same in writing) any
right, power or privilege hereunder shall operate as a waiver thereof, nor shall
any single or partial exercise of any such right, power or privilege preclude
any other or further exercise thereof, or the exercise of any other right, power
or privilege. The remedies provided herein are cumulative and not exclusive of
any remedies provided by law. The Collateral Agent, acting on behalf of the
Secured Parties, shall have all of the rights and remedies granted under the
Intercreditor Agreement or any Finance Document, and available at law or in
equity, and these same rights and remedies may be pursued separately,
successively or concurrently against the Pledgor or any Collateral, at the
discretion of the Collateral Agent.

                  20. SEVERABILITY. Any provision of this Pledge Agreement which
is prohibited, unenforceable or not authorized in any jurisdiction shall, as to
such jurisdiction, be ineffective to the extent of such prohibition,
unenforceability or non-authorization, without invalidating the remaining
provisions hereof or affecting the validity, enforceability or legality of such
provision in any other jurisdiction. Where provisions of any law or regulation
resulting in such prohibition or unenforceability may be waived they are hereby
waived by the Pledgor and the Collateral Agent to the full extent permitted by
law so that this Pledge Agreement shall be deemed a valid, binding agreement,
and the Security Interest created hereby shall constitute a continuing first
lien on and first perfected security interest in the Collateral, in each case
enforceable in accordance with its terms.

                                      -11-

<PAGE>

                  21. EXCULPATORY PROVISIONS; RELIANCE BY COLLATERAL AGENT.

                           21.1. EXCULPATORY PROVISIONS. Neither the Collateral
Agent, the Funding Company nor any other Secured Party, nor any of their
respective officers, directors, employees, agents, attorneys-in-fact or
affiliates (the "Exculpated Parties") shall be liable to the Pledgor for any
action taken or omitted to be taken by it or them under or in connection with
this Pledge Agreement or any other Transaction Document to which the Pledgor is
a party, except for the Exculpated Parties' own gross negligence or willful
misconduct, or responsible in any manner to any Person for any recitals,
statements, representations or warranties made by the Pledgor or any officer
thereof contained in this Pledge Agreement or any other Transaction Document to
which the Pledgor is a party or in any certificate, report, statement or other
document referred to or provided for in, or received by the Collateral Agent,
the Funding Company or any other Secured Party under or in connection with, this
Pledge Agreement or any other Transaction Document to which the Pledgor is a
party or for the value, validity, effectiveness, genuineness, enforceability or
sufficiency of this Pledge Agreement or any other Transaction Document to which
the Pledgor is a party or for any failure of Pledgor to perform any of the
Obligations. Neither the Collateral Agent, the Funding Company nor any other
Secured Party shall be under any obligation to any Person to ascertain or to
inquire as to the observance or performance of any of the agreements contained
in, or conditions of, this Pledge Agreement or any other Transaction Document to
which the Pledgor is a party, or to inspect the properties or records of the
Pledgor.

                           21.2. RELIANCE BY COLLATERAL AGENT. The Collateral
Agent shall be entitled to conclusively rely, and shall be fully protected in
relying, upon any note, writing, resolution, notice, consent, certificate,
affidavit, letter, cablegram, telegram, telecopy, telex or teletype message,
statement, order or other document or conversation believed by it to be genuine
and correct and to have been signed, sent or made by the proper Person or
Persons and upon advice and statements of legal counsel (including, without
limitation, counsel to Pledgor), independent accountants and other experts
selected by the Collateral Agent. The Collateral Agent shall have no obligation
to any Person to act or refrain from acting or exercising any of its rights
under this Pledge Agreement.

                  22. AMENDMENT. No modification or waiver of any of the
provisions of this Pledge Agreement shall be binding on the Collateral Agent,
except as expressly set forth in a writing duly signed by each party hereto and
delivered by the Collateral Agent and which is otherwise in accordance with
Section 6.2 of the Trinidad Project Loan Agreement.

                  23. SUCCESSORS AND ASSIGNS. This Pledge Agreement shall be
binding upon and inure to the benefit of the Pledgor and the Collateral Agent
for the benefit of the Secured Parties and their respective successors and
assigns. In the event of any assignment or transfer by the Funding Company or
any other Secured Party of any instrument evidencing all or any part of the
Obligations, the holder of such instrument shall, subject to the Trinidad
Project Loan Agreement and the Trinidad Guarantee, be entitled to the benefits
of this Pledge Agreement.

                  24. NUMBER AND GENDER. Whenever used in this Pledge Agreement,
the singular number shall include the plural and the plural the singular, and
the use of any gender shall be applicable to all genders.

                  25. SUBROGATION, ETC. Notwithstanding any payment or payments
made by the Pledgor or the exercise by the Collateral Agent of any of the
remedies provided under this Pledge Agreement or any of the Finance Documents,
the Pledgor shall have no claim (as defined in 11 U.S.C. Section 101(5)) of
subrogation to any of the rights of the Secured Parties against the Company, the
Pledgor or any Collateral or guaranty held by the Secured Parties for the
satisfaction of any of the Obligations, nor shall the Pledgor have any claims
(as defined in 11 U.S.C. Section 101(5)) for reimbursement, indemnity,
exoneration or

                                      -12-

<PAGE>

contribution from the Company in respect of payments made by the Pledgor
hereunder. Notwithstanding the foregoing, if any amount shall be paid to the
Pledgor on account of such subrogation, reimbursement, indemnity, exoneration or
contribution rights at any time, such amount shall be held by the Pledgor in
trust for the Secured Parties, segregated from other funds of the Pledgor, and
shall be turned over to the Collateral Agent for the benefit of the Secured
Parties, in the exact form received by the Pledgor (duly endorsed by the Pledgor
to the Collateral Agent for the benefit of the Secured Parties, if required), to
be applied against such amounts in such order as the Collateral Agent may elect.

                  26. CAPTIONS. The captions, headings and table of contents
used in this Pledge Agreement are for convenience only and do not and shall not
be deemed to affect, limit, amplify or modify the terms and provisions hereof.

                  27. APPLICABLE LAW; JURISDICTION.

                           (a) This Pledge Agreement shall be governed by, and
         construed and interpreted in accordance with, the laws of the State of
         New York applicable to contracts to be wholly performed within such
         state.

                           (b) Any legal action or proceeding against the
         Pledgor with respect to this Pledge Agreement may be brought in the
         courts of the State of New York in the County of New York or of the
         United States for the Southern District of New York and, by execution
         and delivery of this Pledge Agreement, the Pledgor hereby irrevocably
         accepts for itself and in respect of its property, generally and
         unconditionally, the jurisdiction of the aforesaid courts. The Pledgor
         agrees that a judgement, after exhaustion of all available appeals, in
         any such action or proceeding shall be conclusive and binding the
         Pledgor, and may be enforced in any other jurisdiction by a suit upon
         such judgment, a certified copy of which shall be conclusive evidence
         of the judgement. The Pledgor hereby irrevocably designates, appoints
         and empowers Corporation Service Company with offices on the date
         hereof at Two World Trade Center, New York, New York 10048-0203, as its
         designee, appointee and agent to receive, accept and acknowledge for
         and on its behalf, and in respect of its property, service of any and
         all legal process, summons, notices and documents which may be served
         in any such action or proceeding. If for any reason such designee,
         appointee and agent shall cease to be available to act as such, the
         Pledgor agrees to designate a new designee, appointee and agent in New
         York City on the terms and for the purposes of this provision
         satisfactory to the Bond Trustee. The Pledgor further irrevocably
         consents to the service of process out of any of the aforementioned
         courts in any such action or proceeding by the mailing of copies
         thereof by registered or certified mail, postage prepaid, to the
         pledgor at its address set forth in SECTION 16, such service to become
         effective 30 days after such mailing. Nothing herein shall affect the
         right of the Funding Company to serve process in any other manner
         permitted by law or to commence legal proceedings or otherwise proceed
         against the Pledgor in any other jurisdiction.

                           (c) The Pledgor hereby irrevocably waives any
         objection which it may now or hereafter have to the laying of venue of
         any of the aforesaid actions or proceedings arising out of or in
         connection with this Pledge Agreement or any other Finance Document
         brought in the courts referred to in clause (b) above and hereby
         further irrevocably waives and agrees not to plead or claim in any such
         court that any such action or proceeding brought in any such court has
         been brought in an inconvenient forum.

                  28. CONTINUING SECURITY INTEREST; TERMINATION. This Pledge
Agreement shall create a continuing assignment, pledge and first priority
Security Interest in the Collateral, and shall remain in full force and effect
for the benefit of the Collateral Agent and the other Secured Parties until the
Debt

                                      -13-

<PAGE>

Termination Date. Upon the happening of such event, the Security Interest
granted hereby shall terminate. Upon such termination, the Collateral Agent
shall, upon the request and at the expense of the Pledgor, execute and deliver
to the Pledgor such documents as the Pledgor shall reasonably request to
evidence such termination or expiration.

                  29. PAYMENTS SET ASIDE. To the extent that the Pledgor or the
Trinidad Guarantor or any other Person on behalf of the Pledgor or the Trinidad
Guarantor makes a payment or payments to the Collateral Agent and/or any other
Secured Party, or the Collateral Agent and/or any other Secured Party enforce
the Security Interests or the Collateral Agent exercises its right of set-off,
and such payment or payments or the proceeds of such enforcement or set-off or
any part thereof are subsequently invalidated, declared to be fraudulent or
preferential, set aside and/or required to be repaid to a trustee, receiver or
any other party under any bankruptcy law, state or federal law, common law or
equitable cause, then to the extent of such recovery, the Obligations or any
part thereof originally intended to be satisfied, and this Pledge Agreement and
all Liens, rights and remedies therefor, shall be revived and continued in full
force and effect as if such payment had not been made or such enforcement or
set-off had not occurred.

                  30. COUNTERPARTS. This Pledge Agreement may be executed in any
number of counterparts, each of which shall be an original, with the same effect
as if the signatures thereto and hereto were upon the same instrument.

                  31. NON-RECOURSE. Notwithstanding any other provision hereof,
the Collateral Agent agrees that its only remedy hereunder shall be to proceed
against the Collateral and that there shall be no recourse to the Pledgor, its
shareholders, officers, directors, employees, partners or agents.

                  32. CONFLICTS WITH THE INTERCREDITOR AGREEMENT.
Notwithstanding any other provision hereof, in the event of any conflict between
the terms of this Pledge Agreement and the Intercreditor Agreement, the
provisions of the Intercreditor Agreement shall control.

                                      -14-

<PAGE>


         IN WITNESS WHEREOF, the parties hereto have caused this Pledge
Agreement to be duly executed as of the day and year first written above.



                                     YORK RESEARCH CORPORATION,
                                     a Delaware corporation



                                     By: /s/ Michael Trachtenberg
                                        ---------------------------
                                        Name: Michael Trachtenberg
                                        Title: Executive Vice President




                                     THE BANK OF NEW YORK,
                                     as Collateral Agent


                                     By: /s/ Joseph Ernst
                                        ---------------------------
                                        Name: Joseph Ernst
                                        Title: Vice President

                                      -15-