MEXICO CITY, March 27 (Reuters) - Latin American stocks fell on Tuesday after sharp sell-offs on Wall Street led by tech companies plagued by uncertainty over government regulation and privacy questions surrounding Facebook.

The S&P 500 fell by 1.73 percent, with Facebook shares shedding 4.9 percent, bringing the company's stock down nearly 15 percent for the month. The Nasdaq Internet index saw its biggest daily percentage drop since June 2016.

Meanwhile, the MSCI Latin American stocks index closed down 1.29 percent, with share indices sliding steeply in Brazil, Colombia and Argentina.

Both Brazil's real and the Mexican peso gave ground against the dollar, which rose against a basket of major currencies as fears of a trade war receded.

"Mexico's financial markets ended the day down, still affected by slight concerns among investors about the possible emergence of a global trade war," CI Banco said in a note to clients.

Mexico's S&P/BMV IPC stock index closed down 0.14 percent, with shares in cement maker Cemex retreating by more than 2 percent. By contrast, stock in Santander Mexico rose almost 3.5 percent.

Earlier in the day, the Mexican peso reached its strongest level since October, touching 18.27 per dollar.

Brazil's Bovespa slipped by 1.5 percent, with the worst performer public water and sewage firm SABESP, whose stock tumbled by 8.62 percent after regulators in Sao Paulo proposed adjustments to tariff rates.

In Argentina, the interbank peso rose by 0.10 percent, supported by continuing interventions by the country's central bank. By Monday, the central bank had sold nearly $1.8 billion of its reserves during the month.

Key Latin American stock indexes and currencies at 2200 GMT: Stock indexes Latest daily % change YTD % change MSCI Emerging 1185.18 0.25 2.31 Markets MSCI LatAm 2996.25 -1.29 5.94 Brazil Bovespa 83808.06 -1.5 9.69 Mexico IPC 46793.58 -0.14 -5.19 Chile IPSA 5480.31 -0.62 -1.51 Chile IGPA 27463.33 0.5 -1.85 Argentina MerVal 31236.12 -1.27 3.89 Colombia IGBC 11301.39 -1.83 -0.61 Currencies Latest daily % change YTD % change Brazil real 3.3314 -0.84 -0.54 Mexico peso 18.385 -0.25 7.15 Chile peso 604.3 0.12 1.71 Colombia peso 2784.5 0.54 7.09 Peru sol 3.226 -0.28 0.34 Argentina peso 20.1675 0.10 -7.77 (interbank) Argentina peso 20.71 0.58 -7.15 (parallel) (Writing by Dave Graham; Editing by Sandra Maler)