<PAGE>

                                                                    Exhibit 10.5

                                                             JPMORGAN CHASE BANK

[JPMORGAN LOGO]


                                    GUARANTY

                                                              New York, New York
                                                                  April 30, 2002

     WHEREAS, LEVCOR INTERNATIONAL, INC. (the "Borrower"), desires to transact
business with and to obtain credit or a continuation of credit or other
financial accommodations from JPMORGAN CHASE BANK, a New York banking
corporation (the "Bank"); and

     WHEREAS, the Bank is unwilling to extend or continue credit to or other
financial accommodations to the Borrower, unless it receives the following
guaranty of the undersigned;

     NOW, THEREFORE, in consideration of the premises and of other good and
valuable consideration and in order to induce the Bank from time to time, in its
discretion, to extend or continue credit or other financial accommodations to
the Borrower, the undersigned hereby guarantees, absolutely and unconditionally,
to the Bank the payment of all liabilities of the Borrower to the Bank of
whatever nature pursuant to that certain Promissory Note dated April   ,2002 in
the principal amount of $3,000,000 made by the Borrower payable to the Bank and
any renewals, extensions or modifications thereof, whether now existing or
hereafter incurred, whether matured or unmatured, secured or unsecured and
whether absolute or contingent, including, without limitation, all interest or
other claims which may accrue or arise after the commencement of bankruptcy,
insolvency, reorganization, liquidation or other similar proceedings (all of
which are hereinafter collectively referred to as the "Liabilities of the
Borrower").

     The undersigned agrees that, with or without notice or demand, the
undersigned shall reimburse the Bank for all the Bank's expenses (including
reasonable fees of counsel for the Bank who may be employees thereof) incurred
in connection with any of the Liabilities of the Borrower or the collection
thereof.

     This guaranty is a continuing guaranty and shall remain in full force and
effect irrespective of any interruptions in the business relations of the
Borrower with the Bank; provided, however, that the undersigned may, by notice
in writing, delivered personally or received by certified mail, return receipt
requested, addressed to the Bank's office at 1111 Fannin Street, Houston, Texas
77002, Commercial Loan Documentation Division, Attention: Manager, terminate
this guaranty, but any such termination shall have no effect with respect to the
Liabilities of the Borrower (including contingent liabilities) existing on the
date on which such notice is so delivered or received or which on such date the
Bank is obligated (including on a conditional basis) to provide or acquire
thereafter, or with respect to any interest, fees, indemnities, charges,
expenses or costs payable thereon or attributable thereto even if arising or
incurred after such date, and this guaranty and the obligations of the
undersigned hereunder

<PAGE>

with respect to the foregoing Liabilities of the Borrower shall continue
notwithstanding any such termination until all such amounts are fully and
finally paid.

     All monies available to the Bank for application in payment or reduction of
the Liabilities of the Borrower may be applied by the Bank in such manner and in
such amounts and at such time or times as it may see fit to the payment or
reduction of such of the Liabilities of the Borrower as the Bank may elect.

     The undersigned hereby waives: (a) notice of acceptance of this guaranty
and of extensions of credit or other financial accommodations by the Bank to the
Borrower; (b) presentment and demand for payment of any of the Liabilities of
the Borrower; (c) protest and notice of dishonor or default to the undersigned
or to any other party with respect to any of the Liabilities of the Borrower;
(d) all other notices to which the undersigned may otherwise be entitled; and
(e) any demand for payment hereunder.

     All liabilities of the undersigned to the Bank hereunder or otherwise,
whether or not then due or absolute or contingent, shall without notice or
demand become due and payable immediately upon the occurrence of any default or
event of default with respect to any Liabilities of the Borrower (or the
occurrence of any other event which results in acceleration of the maturity of
any thereof) or the occurrence of any default hereunder. This is a guaranty of
payment and not of collection and the undersigned further waives unconditionally
and irrevocably any right to require that any action be brought against the
Borrower or any other person or to require that resort be had to any security or
any other property or asset or to any balance of any deposit account or credit
on the books of the Bank in favor of the Borrower or any other person prior to
any payment under this guaranty being made or enforced.

     The undersigned hereby consents that from time to time, before or after
any default by the Borrower or any notice of termination hereof, with or without
further notice to or assent from the undersigned, any security at any time held
by or available to the Bank for any obligation of the Borrower, or any security
at any time held by or available to the Bank for any obligation of any other
person secondarily or otherwise liable for any of the Liabilities of the
Borrower, may be exchanged, surrendered or released and any obligation of the
Borrower, or of any such other person, may be changed, altered, renewed,
extended, continued, surrendered, compromised, waived, discharged or released in
whole or in part (including without limitation any such event resulting from any
insolvency, bankruptcy, reorganization or other similar proceeding affecting the
Borrower or its assets) or any default with respect thereto waived, and the Bank
may fail to set off and may release, in whole or in part, any balance of any
deposit account or credit on the Bank's books in favor of the Borrower, or of
any such other person, and may extend further credit in any manner whatsoever to
the Borrower, and generally deal or take action or no action with regard to the
Borrower or any such security or other person as the Bank may see fit; and the
undersigned shall remain bound under this guaranty notwithstanding any such
exchange, surrender, release, change, alteration, renewal, extension,
continuance, compromise, waiver, discharge, inaction, extension of further
credit or other dealing.

     The obligations of the undersigned are absolute and unconditional and are
valid irrespective of any amendment, modification, waiver, consent or other
change, discharge or

                                       2
<PAGE>

release (including by operation of law, regulation or legal proceedings) with
respect to, or any lack of validity or enforceability of, any Liabilities of the
Borrower, or with respect to any other guaranty thereof or other credit support
thereto or any collateral securing any of the foregoing, or any other agreement
or circumstance which might otherwise constitute a defense to the obligations
hereunder to any of the Liabilities of the Borrower or to the obligations of
others related hereto or thereto and the undersigned irrevocably waives the
right to assert defenses, set-offs and counterclaims in any litigation relating
to this guaranty and the Liabilities of the Borrower. This guaranty sets forth
the entire understanding of the parties, and the undersigned acknowledges that
no oral or other agreements, conditions, promises, understandings,
representations or warranties exist in regard to the obligations hereunder,
except those specifically set forth herein.

     The undersigned irrevocably waives and shall not seek to enforce or collect
upon any rights which it now has or may acquire against the Borrower, either by
way of subrogation, indemnity, reimbursement or contribution, or any other
similar right, for any amount paid under this guaranty or by way of any other
obligations whatsover of the Borrower to the undersigned. In the event either a
petition is filed under the Bankruptcy Code in regard to the Borrower or an
action or proceeding is commenced for the benefit of the creditors of the
Borrower, this agreement shall at all times thereafter remain effective in
regard to any payments or other transfers of assets to the Bank received from or
on behalf of the Borrower prior to notice of termination of this guaranty and
which are or may be held voidable or otherwise subject to recission or return on
the grounds of preference, fraudulent conveyance or otherwise, whether or not
the Liabilities of the Borrower have been paid in full.

     Each reference herein to the Bank shall be deemed to include its successors
and assigns, in whose favor the provisions of this guaranty shall also inure.
Each reference herein to the undersigned shall be deemed to include the heirs,
executors, administrators, legal representatives, successors and assigns of the
undersigned, all of whom shall be bound by the provisions of this guaranty.

     No delay on the part of the Bank in exercising any rights hereunder or
failure to exercise the same shall operate as a waiver of such rights; no notice
to or demand on the undersigned shall be deemed to be a waiver of the obligation
of the undersigned or of the right of the Bank to take further action without
notice or demand as provided herein; nor in any event shall any modification or
waiver of the provisions of this guaranty be effective unless in writing signed
by an authorized officer of the Bank; nor shall any such waiver be applicable
except in the specific instance for which given.

     This guaranty is, and shall be deemed to be, a contract entered into under
and pursuant to the laws of the State of New York and shall be in all respects
governed, construed, applied and enforced in accordance with the laws of the
State of New York; and no defense given or allowed by the laws of any other
State or Country shall be interposed in any action hereon unless such defense is
also given or allowed by the laws of the State of New York.

                                       3

<PAGE>

     The undersigned hereby unconditionally WAIVES ANY RIGHT TO JURY TRIAL in
connection with actions by or against the Bank arising out of or in connection
with the Liabilities of the Borrower and this guaranty.


                                    /s/ Robert A. Levinson
                                    -----------------------------------
                                        ROBERT A. LEVINSON


STATE OF NEW YORK    )
                     ) SS:
COUNTY OF NEW YORK   )

On the 29th day of April, 2002, before me personally came ROBERT A. LEVINSON,
to me known to be the individual described in and who executed the foregoing
instrument and he acknowledged to me that he executed the same.


                                      /s/ Ann M. Hankins
                                      ----------------------------------------
                                      Notary Public

                                      My commission expires:

                                               ANN M. HANKINS
                                      NOTARY PUBLIC, State of New York
                                               No. 01HA4727607
                                         Qualified in New York County
                                      Commission Expires Sept. 30, 2002



                                       4