EMERGING MARKETS-Fed's Yellen speech provides some balm for Latam assets

(Recasts after Yellen speech, updates prices) By Bruno Federowski SAO PAULO, March 29 (Reuters) - Mexico's peso and stock market rose on Tuesday, erasing earlier losses, following comments by Federal Reserve Chair Janet Yellen who said the U.S. central bank should proceed cautiously in deciding to raise interest rates. Latin American currencies had fallen after opening, on fears Yellen could reinforce the Fed's intention to raise rates sooner rather than later, a move which could