By Susan Mathew April 22 (Reuters) - Most Latin American stocks dipped in lackluster trade on Monday, in line with world stocks, while Brazil's real rose slightly as investors were encouraged that congress will take up a pension overhaul, while Colombia's peso rose as surging oil prices supported the crude exporter.
Returning from Easter extended holidays, stocks in Mexico were little changed while Argentina shares tumbled nearly 4 percent, as Wall Street's lower open tacked on to a dip in Asia shares earlier in the day.
Brazil shares fell 0.7 percent, driven by a 2.5 percent decline in mining major Vale on reports that a state parliamentary committee was considering raising a tax on miners in response to the burst of a Vale-owned dam earlier this year which left hundreds dead.
Brazil's currency rose as the proposed pension overhaul was to be up for discussion at a congressional committee on Tuesday, after being delayed by a week. But the real gave back most early gains to trade just slightly higher as investors were nervous that possible changes to the plan could dilute projected savings.
Meanwhile, threat of a possible truckers' strike over high diesel prices loomed after Brazilian state-run oil firm Petroleo Brasileiro hiked prices last week.
A similar strike last year paralyzed Brazil's economy for weeks, led to the departure of the then-CEO at Petrobras and handicapped the government. President Jair Bolsonaro, who took over in January, has been sensitive to the truckers' concerns.
"It's an important issue, there's no expectation that it will happen, but if it does, it can signal to the market that there is even more lack of articulation in government than was previously thought," a trader at a national brokerage firm said.
Currencies of Mexico and Chile both slipped more than 0.3 percent against a weaker dollar, while the Argentine peso lost more than 2 percent with a JP Morgan risk indicator rising to its highest figure during the presidency of Mauricio Macri who took office in December 2015.
Surging oil prices helped net crude exported Colombia's peso tick marginally higher.
Key Latin American stock indexes and currencies at 1531 GMT: Stock indexes Latest Daily % change MSCI Emerging Markets 1089.04 -0.32 MSCI LatAm 2752.83 -0.11 Brazil Bovespa 94121.30 -0.48 Mexico IPC 45505.31 -0.04 Chile IPSA 5246.30 -0.29 Argentina MerVal 30779.98 -3.92 Colombia IGBC 12853.73 0.4 Currencies Latest Daily % change Brazil real 3.9255 0.08 Mexico peso 18.8433 -0.44 Chile peso 664.4 -0.38 Colombia peso 3148.85 0.09 Peru sol 3.305 -0.24 Argentina peso 42.6600 -1.78 (interbank) (Reporting by Susan Mathew in Bengaluru and Laís Martinsin Sao Paulo; Editing by David Gregorio)