American Financial Group Inc. on Wednesday announced it had agreed to sell its annuity business to Massachusetts Mutual Life Insurance Co. in a $3.5 billion cash deal. The acquisition will deliver new ways for MassMutual, one of the nation’s oldest life insurers, to sell its products. MassMutual has long had one of the biggest fleets of career agents in the United States, and the deal will add opportunities to sell through banks, independent broker dealers and independent agents, analysts said. American Financial said the transaction will mark its exit from the market for fixed and indexed annuities, which are popular retirement products with conservative savers. It will focus more tightly on its property and casualty insurance operations. Under the terms of the agreement, which is expected to close in the second quarter of 2021, MassMutual will acquire Great American Life Insurance Co. and its two insurance subsidiaries, Annuity Investors Life Insurance Co. and Manhattan National Life Insurance Co. As of Dec. 31, 2020, Great American and its subsidiaries had about $40 billion of traditional fixed and indexed annuity reserves.