An Ohio health carrier plans to buy a small local health insurer.

Medical Mutual of Ohio, Cleveland, has agreed to acquire Summit Insurance Company from Upper Valley Medical Center, Troy, Ohio, for a price that was not immediately available.

Summit, formed in 1992, now provides health coverage for about 900 groups with about 20,000 members.

Upper Valley began looking into the possibility of selling Summit in 2005 because of Summit’s small size, according to company executives.