WAIVER TO CREDIT AGREEMENT
This WAIVER TO CREDIT AGREEMENT dated as of May 12, 2000, (the "Waiver"), is entered into among
ZOLTEK COMPANIES, INC., a Missouri corporation ("Parent"), ZOLTEK CORPORATION, a Missouri
corporation, ZOLTEK INTERMEDIATES CORPORATION, a Missouri corporation, ZOLTEK
PROPERTIES, INC., a Missouri corporation, CAPE COMPOSITES, INC., a California corporation, and
ENGINEERING TECHNOLOGY CORPORATION, a Missouri corporation (each, individually a "Borrower"
and, collectively, the "Borrowers"), the LENDERS listed on the signature pages hereof and MERCANTILE
BANK NATIONAL ASSOCIATION, now known as Firstar Bank, in its capacity as Agent for the Lenders.
WHEREAS, the Borrowers, the Lenders and the Agent are parties to that certain Credit Agreement dated as of
November 19, 1999 (the "Agreement") pursuant to which the Lenders have made available to Borrower a credit
facility in the maximum aggregate principal amount of Seventy One Million Dollars ($71,000,000); and
WHEREAS, Borrowers have requested the Lenders and the Agent to waive compliance with certain of the
provisions of the Agreement; and
WHEREAS, the Required Lenders and the Agent desire to waive compliance with certain provisions of the
Agreement as requested by the Borrower;
NOW, THEREFORE, in consideration of the premises and the mutual agreements herein set forth and other
good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties
hereto agree as follows:
Section 1. Definitions. Capitalized terms used and not otherwise defined in this Waiver are used as defined in the
Section 2. Waivers under the Agreement.
2.1 The Lenders and the Agent hereby waive the provisions of Section 7.1(i)(i) of the Agreement solely to the
extent necessary to waive the failure by Borrowers to attain, as of March 31, 2000, EBITDA (as calculated on a
consolidated basis for Parent and its Consolidated Subsidiaries) of not less than $12,000,000.
2.2 The Lenders