BOSTON, Nov 2 (Reuters) - Robert Mercer, a billionaire hedge fund manager who has supported conservative causes, said on Thursday that he plans to step down as co-chief executive officer at Renaissance Technologies in January.
Mercer, 71, told investors in a letter that Peter Brown, with whom he has shared to top job for eight years will continue on as chief executive officer. Mercer will also step down from the board but continue to work at the firm, focusing on research. Reuters saw a copy of the letter. (Reporting by Svea Herbst-Bayliss)