Frederick C. Castellani will assume the helm of MassMutual Retirement...

Frederick C. Castellani will assume the helm of MassMutual Retirement Services. He was head of the division’s sales. Robert W. Kumming will become the new head of sales. Mr. Castellani’s promotion to senior vice president of MassMutual Retirement Services came after his predecessor, John V. Murphy, executive vice president, was given increased responsibilities at Massachusetts Mutual Life.