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.