* Fed vows to maintain bond-buying until substantial recovery * Peso steady after lawmakers delay c.bank bill * Analysts divided about Mexico rate cut on Thursday * Argentine stocks and bonds rise, awaiting IMF talks outcome (Adds comment, details; updates prices) By Medha Singh Dec 16 (Reuters) - Most Latin American currencies were muted against a perky dollar on Wednesday as the U.S. Federal Reserve promised to keep supporting financial markets to fight the recession, while stocks in the region climbed to fresh nine-month highs. The U.S. central bank raised its outlook for economic growth next year to 4.2% from 4% at the median and lowered the expected year-end unemployment rate. The greenback touched session highs, pressuring the Brazilian real, Colombian and the Mexican peso . Attention turns to the Mexican central bank meeting on Thursday where policymakers are widely expected to leave benchmark interest rates unchanged despite slowing inflation, a Reuters poll showed. The Mexican peso strengthened past the 20-per-dollar barrier in the previous session as Mexican lawmakers agreed to postpone debating a divisive new central bank law that critics say could force the bank to buy laundered narcotics proceeds. President Andres Manuel Lopez Obrador said that it was a good decision to postpone the bill. A majority of the analysts and economists surveyed said they expect the Bank of Mexico to hold rates steady at 4.25%, but a few expect it to cut rates by 25 basis points. "Mexico stands alone among LATAM majors as a country with additional material scope for monetary policy easing, through rate cuts," said Gustavo Rangel, chief economist for Latin America at ING. He expects Banxico to stand pat this week. "Real rates remain unusually high in Mexico, when compared to its regional peers. This suggests that Banxico will likely be under pressure to consider additional rate cuts throughout 2021," Rangel said. The Argentine peso slipped in a controlled depreciation to a historic low of 82.63 per dollar while stocks and sovereign bonds were higher as investors awaited progress in talks with the International Monetary Fund for a loan program. The Chilean peso climbed 0.2% as Pfizer Inc and BioNTech SE"s coronavirus vaccine received approval for emergency use in the country. Prices for copper, Chile"s major export, also inched toward eight-year highs on optimism about strong demand in top consumer China. An index of Latin American stocks rose 1.9% to its highest level since March 5. Key Latin American stock indexes and currencies: Stock indexes daily % change Latest MSCI Emerging Markets 1263.28 1.05 MSCI LatAm 2447.04 1.27 Brazil Bovespa 117661.95 1.3 Mexico IPC 43758.49 0.49 Chile IPSA 4110.99 1.21 Argentina MerVal 53194.77 -0.16 Colombia COLCAP 1418.92 0.77 Currencies daily % change Latest Brazil real 5.1173 -0.64 Mexico peso 19.9450 -0.29 Chile peso 734.2 0.23 Colombia peso 3418.11 -0.03 Peru sol 3.5867 -0.05 Argentina peso (interbank) 82.6200 -0.10 (Reporting by Medha Singh and Shashank Nayar in Bengaluru; editing by Jonathan Oatis and Mark Heinrich)