Charles P. Mayer joined Pioneer Investment Management USA as executive vice president and director of U.S. portfolio management, a new position. He oversees U.S. equities and fixed income, international investments, trading and investment communications. He reports to Osbert Hood, CEO, and to Giordano Lombardo, CIO of Pioneer Global Asset Management. Mr. Mayer was CIO for Bel Air Investment Advisors. Michael Sanchez, spokesman for Bel Air, could not be reached for comment by press time on whether he'll be replaced.