* Copper prices hit 7-year peak * Real firms for a second day * Mexican peso muted after dismal growth forecast (Adds details, updates prices) By Sruthi Shankar and Ambar Warrick Nov 25 (Reuters) - A spike in copper prices saw Chile"s peso outperforming Latin American currencies on Wednesday, while most other regional stocks and units continued to grind higher on optimism over a coronavirus vaccine. The peso jumped 1.2% to the dollar and was set for its best day in more than one month. Prices of copper, Chile"s top export, reached a seven-year peak on expectations of strong demand from major buyer China. A pickup in Chinese industrial activity has improved the outlook for commodity demand, spurring gains in oil and metal prices. The Colombian peso gained 0.5% as oil prices rose. But gains in oil exporter Mexico"s currency were held back after the central bank revised down its outlook for 2021 economic growth, but also tempered its most pessimistic views about growth this year despite the damage from the pandemic. Investors have rushed to riskier emerging market assets in recent weeks after positive data on COVID-19 vaccine efficacy and signs of stability in U.S. politics. But the economic ructions from the outbreak continue to be felt. Growing infection rates in the Americas also raised concerns over possible new lockdown measures to curb the spread of the novel coronavirus. Brazil"s real firmed for a second session, rising about 1%after figures showed the country"s current account deficit narrowed to its smallest in 2-1/2 years in October, helped by a bigger-than-expected surplus in goods trade. Worries about Brazil"s fiscal health, record-low interest rates and a second wave of coronavirus cases have hammered the real this year, but a brighter global mood has boosted the currency by more than 7% in November. "While there has been already very strong positive news flow surrounding the vaccine, we do not believe that the vaccine trade is already done yet," Citi"s Dirk Willer said in a note. "Pullbacks, maybe related to month end equity selling, should be seen as a buying opportunity." Stocks in the region edged higher, with Brazil"s Bovespa index adding about 0.4%. A Reuters poll showed Brazilian stocks will reach pre-pandemic levels by the middle of next year, but concern about the impact of a resurgent pandemic could limit the recovery. Latin American stock indexes and currencies: Latest Daily % change MSCI Emerging Markets 1218.94 -0.58 MSCI LatAm 2243.12 0.74 Brazil Bovespa 110352.93 0.52 Mexico IPC 42319.68 -0.98 Chile IPSA 4135.16 -1.48 Argentina MerVal 54238.77 0.19 Colombia COLCAP 1264.24 -0.5 Currencies Latest Daily % change Brazil real 5.3212 1.00 Mexico peso 19.9730 0.13 Chile peso 764.4 1.18 Colombia peso 3615.7 0.51 Peru sol 3.603 0.17 Argentina peso 80.7900 -0.11 (interbank) (Reporting by Sruthi Shankar and Ambar Warrick in Bengaluru; editing by Jonathan Oatis and Grant McCool)