Exclusive: American Century hires Ameriprise executive as COO By Jessica Toonkel NEW YORK (Reuters) - American Century Investments has hired Patrick Bannigan, an Ameriprise Financial (AMP.N) executive, as its new chief operating officer. Bannigan was formerly president of RiverSource Funds, part of Ameriprise's Columbia Management division. He is replacing Barry Fink, who is retiring in mid February. Fink will help with the transition, an American Century spokesman said on Tuesday. Bannigan started at American Century on Monday, the spokesman said. An Ameriprise spokesman did not return requests for comment. Bannigan has more than 20 years of experience working in asset management. Prior to joining RiverSource, he was managing director and global head of product for Morgan Stanley's (MS.N) investment management division. Bannigan will report to Jonathan Thomas, president and CEO of American Century, who is also a veteran of Morgan Stanley's investment management division. American Century had $124 billion in assets as of September 30. Reporting by Jessica Toonkel; Editing by Phil Berlowitz