EMERGING MARKETS-Mexico peso rallies as ministers put brave face on NAFTA talks

(Recasts with peso gains, updates prices) By Miguel Gutierrez MEXICO CITY, Oct 17 (Reuters) - Mexico's peso surged on Tuesday after aggressive U.S. demands appeared to have not yet sunk hopes of reaching a new North American trade deal while stocks in Brazil fell on worries the country's president could face a corruption trial. Mexico's peso gained about 1.5 percent after trade ministers from the United States, Canada and Mexico wrapped up a contentious round of talks and said they