Great American Financial Group Inc. has agreed to pay $205 million in cash for Ceres Group Inc., a seller of health insurance and Medicare supplement insurance.

Great American, Cincinnati, the parent of companies such as Great American Life Insurance Company and Annuity Investors Life Insurance Company, already has a substantial Medigap operation.

Acquiring Ceres, Cleveland, a company with about $775 million in assets, should make Great American one of the top 10 sellers of Medigap products, according to Great American President S. Craig Lindner.

Great American is “continuing to look for opportunities to grow and strengthen our core businesses through acquisitions,” Lindner said in a statement about the Ceres deal.

Tom Kilian, president of Ceres, says Ceres is making the deal to maximize value for shareholders and make Ceres part of a company that will have a larger presence in the senior market.

Great American and Ceres hope to complete the deal later this year.

The Ceres board already has approved the deal, but the deal still must be approved by Ceres shareholders and by insurance regulators in Ohio and Nebraska.

Ceres has about 600 employees in Cleveland and offices in Mission, Kan., and Omaha, Neb.