Maryam Muessel was named product CIO and head of U.S. fixed income and...

Maryam Muessel was named product CIO and head of U.S. fixed income and structured credit at Fortis Investments, a new position. She will focus on collateralized debt and loan obligations, said CEO William L. Braman. Ms. Muessel was COO and head of CDO/asset management at ACA Financial Guaranty. Her responsibilities were taken over by William Tomljanovic, executive vice president and senior manager of ACA's customized solutions business, said Cathy Bailey, marketing director.