Former CBS Evening News anchor Dan Rather fired another salvo Monday in his efforts to pursue damages against his former employers.

Rather sued Leslie Moonves, CBS Corp.'s (CBS) chief executive, and Andrew Heyward, CBS News's former president, for fraud in New York State Supreme Court in Manhattan Monday, seeking $20 million in compensatory damages and $50 million in punitive damages.

Last month, a state judge reinstated a fraud claim by Rather in a separate $70 million lawsuit against CBS.

Rather has alleged in part that CBS violated his contract by failing to provide him enough airtime on "60 Minutes" or "60 Minutes II" after removing him as anchor of CBS Evening News in March 2005 following a controversy over a 2004 report about President George W. Bush's service in the Texas Air National Guard.

Rather, who first joined CBS News in 1962, also claims CBS conducted a biased investigation - instead of the independent probe it promised into the underlying story and its production. Rather left the network in June 2006.

The new lawsuit claims CBS's wrongful actions were directed by Moonves, Heyward and Sumner Redstone, chief executive of Viacom Inc. (VIA), CBS's then-corporate parent. Redstone is not a defendant in the new lawsuit.

CBS was spun off from Viacom in 2006.

Moonves, Heyward and Redstone were previously dismissed as defendants in Rather's case against CBS, which was originally filed in 2007.

"Most of Rather's claims already have been rejected by the court - including all his previous claims against Messrs. Moonves and Heyward," CBS said in a statement Monday. "From even a cursory review of the latest complaint, it's clear that the new claim is deficient, as well. We will move to dismiss and are confident we will prevail."

-By Chad Bray, Dow Jones Newswires; 212-227-2017; chad.bray@dowjones.com