His nomination to lead Homeland Security is not the only casualty of Bernard Kerik's Nannygate and other alleged improprieties:

Former police commissioner and U.S. homeland security nominee Bernard Kerik said Wednesday he will leave Giuliani Partners, former Mayor Rudolph Giuliani's consulting firm.

At a news conference in Manhattan, Kerik said he had apologized to Giuliani for being a distraction because of his messy withdrawal as a candidate to head the Department of Homeland Security.

The former New York corrections commissioner said he told Giuliani his resignation would be effective immediately. He said he would seek other unspecified business opportunities.

He did not take questions from reporters.

Kerik's scandal-tarred nomination had become a political embarrassment for Giuliani, a rising star in the GOP who had recommended his friend and business partner to President Bush. At a White House Christmas dinner with Bush nearly two weeks ago, Giuliani apologized to the president for the problems with the Kerik nomination, although he did not meet with Bush for the express purpose of apologizing, his spokeswoman said.

Kerik, 49, was tapped by Bush earlier this month to head the Department of Homeland Security. He abruptly withdrew his name Dec. 10 after revealing that he had not paid all required taxes for a family nanny-housekeeper and that the woman may have been in the country illegally.

A rash of other scandals soon followed, including allegations that he had connections with people suspected of doing business with the mob and accusations that he had simultaneous extramarital affairs with two women.

Recently, the city Department of Investigation said it had been reviewing Kerik's tenure as police commissioner. According to DOI findings, Kerik submitted a background form when he became commissioner of the Department of Correction in 1998 but did not fill one out when he was appointed police commissioner two years later.

After leaving the police department in 2002, Kerik joined Giuliani Partners, becoming a security consultant and then signing on to help launch the Iraqi police force.

Giuliani Partners LLC has advised business and government agencies on security, leadership and other issues. The consulting firm advised Trinidad in its battle against a rise in kidnappings and murders and was paid $4.3 million by Mexico City officials for advice on reducing crime there.

In a statement Wednesday, Giuliani said Giuliani-Kerik LLC, an affiliate of Giuliani Partners, would be renamed Giuliani Security & Safety. Kerik had been CEO of Giuliani-Kerik.