Judith Regan, the former book publisher, says in a lawsuit filed today protesting her dismissal by the News Corporation, the media conglomerate, that a senior executive there encouraged her to lie to federal investigators about her past affair with Bernard B. Kerik after he had been nominated to become homeland security secretary in late 2004.

The lawsuit asserts that the News Corporation executive wanted to protect the presidential aspirations of Rudolph W. Giuliani, Mr. Kerik’s mentor, who had appointed him New York City police commissioner and had recommended him for the federal post.

Ms. Regan makes the charge at the start of a 70-page filing that seeks $100 million in damages for what she says was a campaign to smear and discredit her by her bosses at HarperCollins and its parent company, News Corporation, after her project to publish a book with O.J. Simpson was abandoned amid a storm of protest.

In the civil complaint filed in State Supreme Court in Manhattan, Ms. Regan says the company has long sought to promote Mr. Giuliani’s ambitions. But the lawsuit does not elaborate on that charge, identify the executive who she says pressured her to mislead investigators, or offer details to support her claim.