UPDATE 1-U.S.-based stock funds post $7.6 bln outflows - Lipper

(Adds analyst comments, market performance, table) By Sam Forgione NEW YORK, May 22 (Reuters) - Investors in U.S.-based funds pulled $7.6 billion out of stock funds in the week ended May 21 on weak U.S. economic data and disappointing corporate results, data from Thomson Reuters' Lipper service showed on Thursday. All of the outflows stemmed from stock exchange-traded funds, which posted $9.6 billion in withdrawals, while stock mutual funds attracted $2 billion in net inflows, which