NEW YORK (Standard&Poor's) Nov. 3, 2010--Standard&Poor's Ratings Services today said that General Motors Co.'s announcement that it is launching an IPO of common stock is a positive for the company's future capital-raising prospects, but the announcement has no effect on the rating. On Oct. 7, we assigned our 'BB-' corporate credit rating with a stable outlook on GM. The rating was not dependent on completion of an IPO nor did it reflect any expectation of extraordinary intervention from the current majority shareholder, the U.S. Treasury. The purpose of the IPO is to begin reducing the ownership percentage of GM's three main shareholders: the U.S. Treasury, the United Auto Workers union, and the Canadian government. GM is