January 23, 2007 -- Rudy Giuliani, a 2008 GOP White House front-runner, is moving to sell the Wall Street wing of his multi-pronged business - the strongest sign yet that he's making a serious play for the presidency, The Post has learned. Officials at Giuliani Partners have been meeting quietly with several firms about buying the firm's stake in Giuliani Capital Advisors, an investment banking company, sources familiar with the discussions said. The Chicago-based investment firm is the largest arm of the former mayor's self-named business, and may be the biggest cash cow of Giuliani's four-unit business. But they "get...