EMERGING MARKETS-Latam currencies slip ahead of Yellen speech

By Bruno Federowski SAO PAULO, May 27 (Reuters) - Most Latin American currencies slipped on Friday as traders awaited possible hints about the timing of a U.S. interest rate increase from Federal Reserve Chair Janet Yellen. She is due to speak at an event hosted by Harvard University at 17:15 GMT (1:15 p.m. ET). Several Fed policymakers have stressed recently that market expectations for the pace of rate hikes this year could be too pessimistic. "Yellen may corroborate the hawkis