David Corkins, portfolio manager of the $4.6 billion Janus Mercury Fund, will replace Blaine Rollins as portfolio manager of the flagship $11 billion large-cap growth Janus Fund, effective Feb. 1, said spokesman Blair Johnson. Janus' research team, led by Jim Goff, director of research, will assume management of the Janus Mercury Fund. Mr. Rollins will assume management of the Janus Triton Fund, a $54 million small-cap and midcap growth fund, from Ron Sachs, who will continue to run the $800 million multicap Janus Orion Fund, according to a news release. Under Mr. Rollins, the Janus Fund was in the 67th percentile in the Lipper large-cap growth universe for the 12 months through Dec. 31 and in the 50th percentile for the three years through December; the portfolio manager's small-cap and midcap picks have beaten their benchmarks during those time periods, Mr. Johnson noted. Separately, Jonathan Coleman, portfolio manager of Janus Enterprise Fund, and David Decker, portfolio manager of the Janus Contrarian Fund, have been named co-CIOs of Janus Capital Group‘s U.S. equity growth and core investment disciplines, said Mr. Johnson. The positions are new, and both managers will continue to oversee their existing funds.