Maverick book publisher Judith Regan, fired by HarperCollins last year after her O.J. Simpson book was scrapped, filed a $100 million lawsuit on Tuesday against her former employers accusing them of defamation.

The suit claims publishing house HarperCollins and parent company News Corp. used Regan's dismissal and accusations that she was fired for anti-Semitism to discredit her and ultimately protect former New York Mayor Rudolph Giuliani, the Republican front-runner for U.S. president.

According to the lawsuit, News Corp. feared Regan might disclose damaging information about a longtime Giuliani aide who was once her lover, former New York police commissioner Bernard Kerik, which could in turn embarrass Giuliani.

Kerik was indicted last week on numerous federal corruption charges, including receiving benefits from a company suspected of links to organized crime.

Regan's lawsuit said she stood to accuse Kerik of further misconduct -- namely that he had improperly used his authority to send police detectives to investigate a theft she reported in 2001, while they were involved romantically.

This action arises from a deliberate smear campaign orchestrated by one of the world's largest media conglomerates for the sole purpose of destroying one woman's credibility and reputation, Regan's lawsuit said.

This smear campaign was necessary to advance News Corp.'s political agenda, which has long centered on protecting Rudy Giuliani's presidential ambitions.

The suit, filed in New York State Court, named News Corp., HarperCollins and its chief executive, Jane Friedman. No representatives of either company were immediately available for comment.

Regan sparked a public uproar a year ago when, as head of her own HarperCollins imprint, ReganBooks, she announced plans to release a book by Simpson in which he gave a hypothetical account of killing his ex-wife and her friend.

An accompanying Fox television interview with Simpson by Regan also was planned.

But amid a torrent of criticism that News Corp. was seeking to commercially exploit a grisly double-murder, Chairman Rupert Murdoch personally pulled the plug on the entire deal, canceling both the book and the TV special.

Regan was fired the following month, and News Corp. said later that she was dismissed for making anti-Semitic comments to a HarperCollins lawyer who is Jewish. The company quoted her as having complained that she was the victim of a Jewish cabal after the book deal fell through.

Regan gained prominence in the publishing world by specializing in tell-all celebrity books, including a popular work by adult movie actress Jenna Jameson called How to Make Love Like a Porn Star.

Rights to the book she conceived with Simpson, If I Did It, were later obtained by relatives of Ron Goldman, who was slain in 1994 along with Simpson's former wife, Nicole Brown Simpson, and the book was ultimately published. It became a bestseller.

The former football star, who has maintained his innocence, was acquitted of murder charges in 1995 but later found liable in a wrongful death lawsuit brought the victims' relatives. Regan had said she considered Simpson's book a confession.