* Brazil central bank intervenes in currency markets * Oil, copper prices benefit Chilean, Colombian FX * Latam stocks gain, tracking Wall Street * Argentine assets sink on agriculture export delay (Adds market details, updates prices) By Ambar Warrick Dec 28 (Reuters) - Chilean and Colombian currencies outpaced their Latin American peers in slim trade on Monday, tracking higher copper and oil prices as demand prospects improved after U.S. President Donald Trump signed a coronavirus relief package. Brazil"s real sank as much as 1.8% to a near one-month low to the dollar, prompting central bank intervention to stabilize the currency. The bank had vowed to support the real through the expected year-end unwinding of positions on the currency. The real shrugged off data that showed industrial confidence in December rose to its highest level in over a decade. Trump late on Sunday signed the $2.3 trillion relief and spending bill, which implied positive economic prospects and high near-term liquidity in the world"s largest economy. This in turn fed in to commodity prices, especially copper and oil, even as the rapid spread of the coronavirus weighed on sentiment. Copper and oil demand is considered to be a bellwether of economic outlook. Chile"s peso added 0.2% to the dollar. The country is the world"s largest exporter of copper. Crude exporter Colombia"s peso rose 0.5%. Other currencies in the region retreated, with MSCI"s basket of Latin American currencies shedding 0.7%. Regional stocks rose, tracking record highs on Wall Street. While improving risk appetite and sustained fiscal and monetary support have helped Latin American assets rally off lows hit due to the pandemic, they are still set to end the year lower due to concerns over fiscal health, as well as a second wave of coronavirus infections. Mexico"s peso dropped after the country"s government issued new regulations to limit the ability of private companies to import fuel, according to a weekend decree, fanning concerns that the move may unduly benefit national oil company Petroleos Mexicanos (Pemex). Argentine stocks and the peso tumbled after the loading of more than 140 agricultural export ships in Argentina was stalled by a port-side oilseed workers" strike. Agricultural exports are a crucial source of foreign exchange for the country, which has been struggling to restructure its sovereign debt for most of this year. Most other global risk assets gained as investors cheered a last-minute trade deal signed between Britain and the European Union last week, just seven days before London exits one of the world"s biggest trading blocs. Key Latin American stock indexes and currencies: Latest Daily % change MSCI Emerging Markets 1252.48 -0.22 MSCI LatAm 2428.29 0.13 Brazil Bovespa 119098.33 1.1 Mexico IPC 43792.57 0.97 Chile IPSA 4180.98 1.13 Argentina MerVal 50566.53 -2.039 Colombia COLCAP 1426.89 0.33 Currencies Latest Daily % change Brazil real 5.2576 -1.00 Mexico peso 20.0350 -0.89 Chile peso 711.9 0.22 Colombia peso 3496.25 0.47 Peru sol 3.617 -0.19 Argentina peso 83.9000 -0.64 (interbank) (Reporting by Ambar Warrick and Shashank Nayar in Bengaluru Editing by Jonathan Oatis and Matthew Lewis)