Rudy Gernert, president and CEO of Aegon Institutional Markets, has retired. He will pursue other interests, possibly an entrepreneurial investment venture, said Michele Coan, director of operations and communications. Mr. Gernert retired last week; he could not be reached for further details. Jacqueline Griffin took over as president and CEO, Ms. Cohen said. Ms. Griffin was executive vice president; no information was available on a replacement. Aegon manages $81 billion in stable value, cash, medium-term notes, municipal investments and structured products.