EMERGING MARKETS-Brazil real up; Chile peso at fresh 31-mo high

* Higher copper price lifts Chilean peso to May 2008 level

* Brazil's real adds 0.4 pct, Mexican peso 0.2 pct weaker

* Volumes dwindle as holidays approach (Adds closing prices)

By Samantha Pearson and Maria Jose Latorre

SAO PAULO/SANTIAGO, Dec 20 (Reuters) - Chile's peso hit a 31-month high in weak preholiday trading on Monday as the price of copper, the country's main export, rose sharply.

The higher price for commodities, a key driver in Latin America's rapid growth, also boosted the region's currencies.

But trading is expected to be very light this week as the year draws to a close and investors go on holiday.

The Chilean peso firmed 0.38 percent to 470.20 per dollar, hitting its strongest level since May 2008.

"The peso is still following an appreciation trend, but we don't see the same momentum as in previous days since we are in a period when no one does big deals because of the proximity of the holidays," said one trader in Santiago.

Copper rose toward record highs again on Monday as inflation expectations, robust Chinese demand and supply kinks ahead attracted fund inflows. For details, see [ID:nLDE6BJ0U3]

The Brazilian real closed 0.41 percent stronger at 1.706 reais per dollar on the local spot market.

"The real is going in the opposite direction to most markets abroad but the volume is very, very low," said Andre Ferreira, director of the Futura Corretora brokerage in Sao Paulo. "I'm not seeing any interesting deals."

The currency has gained 2.1 percent so far this year. While the real has underperformed many emerging market currencies, it is still considered one of the most overvalued in the world after steady gains for most of the past decade.

Unlike Chile, Brazil has taken more aggressive measures to slow the local currency's appreciation in an effort to protect local exporters.

"Despite the persistence of tactics by authorities to try to prevent their currencies from strengthening, we retain a broadly positive outlook" for emerging market currencies, said Clyde Wardle, an analyst with HSBC in New York.

"Rather than choosing where to invest, the main task remains correctly choosing where in G10 to fund long (emerging market) positions," he added.

The Mexican currency , which relies less heavily on the commodity trade, was 0.15 percent weaker at 12.4185 per dollar. (Editing by Dan Grebler)