MEXICO CITY — Wal-Mart achieved success in Mexico even as the company’s Mexican chain fought off activists and officials who warned of the dangers of its encroaching influence.

So a bribery probe into Wal-Mart’s store expansion is giving those opponents new ammunition.

Mexico’s largest retailer and biggest private employer went from one Wal-Mart store in 1991 to 2,138 locations this year, including discount centers, grocery stores, restaurants and bodegas. Until recently, it was an investor darling, outpacing Mexico’s benchmark stock index with a more than sixfold return over the past decade.

That changed after The New York Times reported that the retailer had bribed local officials to get stores opened faster in the early 2000s, a revelation that sent shares tumbling 13 percent by Wednesday’s close. For some Mexicans, the allegations confirm their fears that Wal-Mart’s rise would come at a grave cost to their communities.

“We knew that Wal-Mart would bring consequences when it opened in small towns,” said Emma Ortega Moreno, an activist who lost a battle with the retailer over the opening of a store near one of Mexico’s most historic sites, the pyramids of Teotihuacan. “But we didn’t even suspect everything that has come to light.”

Antonio Ocaranza, a spokesman for Wal-Mart de Mexico, said the company benefits local communities.

“We not only generate direct employment where few opportunities exists but also buy local produce and goods, contribute with volunteers to local causes, generate traffic for other local business, and foster new sources of economic growth,” he said.

Wal-Mart de Mexico

Before the scandal hit, Wal-Mart de Mexico was most famous for its relentless growth. Sales reached about $28.8 billion last year, up more than fivefold from a decade ago, as Mexico’s economic growth led to the rise of middle-class consumers. This year, the company plans to open 410 to 436 stores, increasing floor space by 12 percent in Mexico and 9 percent in Central America.

Wal-Mart de Mexico employed 238,128 workers at the end of last year in Mexico and Central America, up 8.4 percent from 2010. That tops the 209,000 jobs in the companies controlled by Mexico’s Carlos Slim, the world’s richest person according to the Bloomberg Billionaires Index.

The retailer has store concepts for several classes of Mexican consumers. Bodega Aurrera