Seventh Amendment to Credit Agreement dated July 14, 1997, as amended and Temporary Waiver

Exhibit 10(k)(7)

National City Bank   

155 East Broad Street 

Columbus, OH 43251 

Thomas E. Redmond

Vice President            

April 18. 2003

Ms. Julie A. Boland

Vice President, Chief Financial Officer

and Treasurer

Oglebay Norton Company

1001 Lakeside Avenue, 15 ^th floor

Cleveland, Ohio 44114-1151

Dear Julie:

Listed below are the terms and conditions related to your request for National City Bank (the “Bank”) to grant a temporary waiver of certain financial covenants in the Credit Agreement dated July 14, 1997, and subsequently amended, by and between ON Marine Services Company, Oglebay Norton Marine Services Company, L.L.C. (collectively, the “Borrower”) and the Bank.

1. Temporary Waiver. Effective upon satisfaction of the conditions set forth below, the Bank temporarily waives any failure by Borrower to comply with the requirements set forth in Sections 5.7 of Exhibit A to the Credit Agreement for the period ending March 31, 2003, including resulting defaults, from the date of occurrence until and including June 15, 2003. The foregoing waiver will become effective upon satisfaction of the following conditions:

a. Both Bank and Borrower shall have executed and delivered this letter agreement; and

b. Borrower shall have paid to Bank a fee of $15,000.00.

2. Amendments to Credit Agreement. The Credit Agreement shall be, and hereby is, amended as follows effective upon the satisfaction of the conditions to the temporary wavier set forth in paragraph 1 above:

a. The Libor Margin and Prime Rate Margin will be increased to 450 basis points and 225 basis points respectively from the time these amendments become effective, to and including August I S, 200

b. Section 5.7 of Exhibit A to the Credit Agreement is amended from the effective date of these amendments until and including June 15, 2003 by incorporating the following financial covenants: