Martin Leibowitz will become managing director of U.S. equity strategy at Morgan Stanley, effective March 1, according to a news release from the firm. It is a new position. Mr. Leibowitz will retire as vice chairman and CIO of TIAA-CREF at the end of this month. Stephanie Cohen Glass, TIAA-CREF spokeswoman, said a replacement for Mr. Leibowitz has not been found, but internal and external candidates are being considered. Mr. Leibowitz joined TIAA-CREF in 1995 after spending 26 years at Salomon Brothers.