Aug. 14 (Bloomberg) -- Wal-Mart Stores Inc. should be probed by federal regulators over reports that company officials broke the law by advising employees against voting Democratic in the November elections, a worker advocacy group said.

Wal-Mart Watch has requested the Federal Election Commission investigate media reports that Wal-Mart managers advised employees against voting for Democratic candidates, according to a letter to the FEC dated Aug. 6. Managers told employees that a Democratic victory could lead to the formation of a union, which might impose fees on workers, the letter said, citing a Wall Street Journal story.

``These are serious actions taken by Wal-Mart which are in violation of federal election law, and we request that you investigate them to the fullest extent possible,'' wrote David Nassar, executive director of Wal-Mart Watch, in the letter.

Wal-Mart denies breaking the law.

If managers gave the impression that Wal-Mart was advising employees how to vote they were ``wrong and acting without approval,'' wrote Wal-Mart spokesman David Tovar in an e-mailed statement.

``We believe that if the FED looks into this, they will find what we've known all along, that we did nothing wrong,'' Tovar wrote.

News about the Wal-Mart Watch letter was earlier reported by the Wall Street Journal. The AFL-CIO and other labor groups plan to submit petitions with 60,000 signatures asking for a probe, the WSJ said.

To contact the reporter on this story: Jeran Wittenstein in San Francisco at jwittenstei1@bloomberg.net.

Last Updated: August 14, 2008 00:57 EDT