Los Angeles (CNN) -- The California State Teachers' Retirement System has filed a derivative action lawsuit against current and former Wal-Mart executives and board members for the firm's alleged bribery in Mexico and a subsequent corporate coverup, the system said Friday.
A derivative action is a lawsuit brought by shareholders on behalf of a company against a third party, and the California entity, which is the second-largest U.S. public pension fund, holds more than 5.3 million shares of Wal-Mart, valued at more than $313.5 million as of Tuesday, according to the fund and its lawsuit.
The lawsuit comes as Wal-Mart says it has been conducting an "extensive investigation" since 2011 into its compliance with a federal law that prohibits American companies from bribing foreign officials.
That Wal-Mart statement came in response to a New York Times article last month alleging that top executives in Wal-Mart's Mexican division attempted to conceal a widespread bribery scheme from the company's headquarters in Bentonville, Arkansas.
The California teachers pension fund's lawsuit, filed in the Court of Chancery in Delaware, alleges that two Wal-Mart executives engaged in opportunistic stock trades between the time the newspaper originally inquired about the story in December 2011 and when publication occurred last month.
The pension fund, which goes by the initials CalSTRS, "believes Wal-Mart's board is dominated by directors beholden to the Walton family rather than shareholders," the fund's governing board said in a statement.
"By utilizing the derivative action, CalSTRS is seeking to remedy the damages sustained by Wal-Mart as a result of alleged gross misconduct by Wal-Mart's executive officers and directors," CalSTRS Chief Executive Officer Jack Ehnes said in a statement. "The focus of this action, unprecedented in CalSTRS history, is corporate governance reform to ensure that similar misconduct is not repeated in the future."
A Wal-Mart spokesman said Friday that the firm is studying the lawsuit.
"We take our responsibility to our shareholders very seriously," spokesman Greg Rossiter said in an e-mail to CNN. "We are reviewing the lawsuit closely and are thoroughly investigating the issues that have been raised."
In response to the newspaper report, another Wal-Mart spokesman said the company has taken a number of steps in Mexico to strengthen its compliance with the U.S. Foreign Corrupt Practices Act.
The Times story alleges that executives at Wal-Mart headquarters -- including former CEO H. Lee Scott -- were more concerned about damage control from the matter than about correcting the situation.
The allegations date back to 2005, when a former Wal-Mart de Mexico executive supposedly e-mailed one of Wal-Mart's senior lawyers, spelling out how the company had paid more than $24 million in bribes to secure construction permits throughout Mexico.
According to the Times, Wal-Mart acted on the information by swiftly conducting its own investigation -- and then just as swiftly moving to conceal it from U.S. and Mexican authorities.
"We are working hard to understand what occurred in Bentonville more than six years ago and are committed to conducting a complete investigation before forming conclusions," David Tovar, Wal-Mart's vice president of corporate communications, said last month.
He added that Wal-Mart has already met with the U.S. Department of Justice and the Securities and Exchange Commission, and that it disclosed the investigation to shareholders in a regulatory filing in December.
The California pension fund's lawsuit says Wal-Mart's alleged "rampant corruption" at its largest foreign subsidiary exposes the company to "potentially hundreds of millions of dollars of liability" for violating the federal law against foreign corruption.
"The significance of the Wal-Mex expansion to Wal-Mart cannot be understated: currently, approximately 20 percent of Wal-Mart's stores (out of more than 10,000 worldwide) are located in Mexico," the lawsuit says.
Wal-Mart's corporate investigators "tracked some $24 million in bribes paid to secure permits and clear away red tape, permitting the rapid expansion of Wal-Mart stores in Mexico," the lawsuit says. "Even worse, they confirmed that the CEO of Wal-Mex, Eduardo Castro-Wright, had approved of the payment of bribes as a business practice, to speed Wal-Mart's entry into the Mexican market and choke out the competition before it had time to establish a foothold."
Castro-Wright has not been disciplined, and his role remains unclear, according to the Times.
Castro-Wright was a popular figure within Wal-Mart, and hailed for his success at Wal-Mart de Mexico, according to the Times. Under his leadership, Wal-Mart de Mexico's net sales grew by 25%, according to a 2005 annual report. Castro-Wright was promoted to chief operating officer of Wal-Mart USA in 2004, quickly moving up to become CEO of the U.S. division a year later. In 2008, he was promoted to vice chairman.
Along with its joint venture partner, Wal-Mart owns 2,099 stores in Mexico, including 213 Walmart Supercenters and 126 Sam's Clubs. Wal-Mart employs nearly 190,000 associates in the country, according to its website.
CNNMoney's Catherine Tymkiw contributed to this report.