Related Party Transactions and Outside Related Director Information

National Interstate Corporation (NATL)

4/11/2006 Proxy Information

We are party to several agreements with Great American Insurance Company, our largest shareholder, relating to reinsurance and underwriting. The terms of these agreements, as described below, were negotiated by National Interstate and Great American Insurance Company. We believe that the terms of these agreements are comparable to those that we could obtain from independent third parties. Additionally, we previously entered into an agreement with Great American Insurance Company and Alan Spachman, our Chairman and President, relating to registration rights and rights of first refusal to buy back their shares in certain circumstances. Our Board of Directors has approved the terms of these agreements. As described in Registration Rights Agreement and Right of First Refusal below, we have filed a registration statement on Form S-3 to register all of the common shares owned by Great American Insurance Company and Alan Spachman.

Mr. Gruber has served as Senior Vice President of Great American Insurance Company, NATL's largest shareholder.

Mr. Kennedy has been the Vice President, Deputy General Counsel and Secretary of American Financial Group, Inc., parent of NATL's largest shareholder, since 1998.

Mr. Larson began his career with American Financial Group, Inc. in 1973 and joined Great American Insurance Company, NATL's largest shareholder, in 1981.