RIO DE JANEIRO, Feb 19 (Reuters) - Latin American currencies mostly weakened against the dollar on Thursday as concerns over Greek debt negotiations and lower oil prices sapped demand for risk assets.
Greece formally requested a six-month extension to its euro zone loan agreement on Thursday but immediately faced strong objections from Germany.
Investors are worried about the potential impact of a Greek default or the country's eventual exit from the euro zone.
"When doubt arises the market has been buying dollars," said Glauber Romano, a currency trader at Sao Paulo's Intercam, adding that concerns over Brazil's stalled economy have also held the real down in recent months.
The Brazilian currency weakened for the second straight session and continued to hover around the 2.85 per dollar level where it has been for over a week.
The currencies of Latin American oil producers Colombia and Mexico tracked global oil prices lower after data showed U.S. crude stocks rose more than twice as much as expected last week, raising additional fears of a supply glut.
Colombia's peso slipped for the fourth straight session, while Mexico's peso fell its most in over a week.
Mexico's central bank revised down its growth outlook for this year and next on Wednesday after the sharp drop in oil prices spurred budget cuts and dampened the outlook for an opening of the country's energy sector.
Brazil's Bovespa stock index traded slightly higher, driven by a 4 percent gain in shares of retailer Lojas Renner SA . (Reporting by Bruno Federowski and Asher Levine; Editing by Meredith Mazzilli)