WHITE PLAINS — A protege of Mayor Giuliani who once led the New York City police department, Bernard Kerik, pleaded not guilty today to a wide-ranging indictment charging him with “selling his office” and lying to cover up the scheme.

Mr. Kerik’s case could prove to be an ongoing embarrassment for Mr. Giuliani, who is seeking the Republican nomination for president.

The indictment accuses Mr. Kerik of conspiring while a public official with a mob-connected construction firm to accept tens of thousands of dollars in renovations to his Bronx apartment, and then lying to cover up the scheme. It also claims he made false statements during his failed bid to head the nation’s homeland security department.

“This is a battle,” Mr. Kerik said, fighting through a media crush as he left court. “I’m going to fight.”

Mr. Kerik surrendered earlier today to the FBI in suburban White Plains, where he was fingerprinted and processed before his court appearance.

Standing before the judge, Mr. Kerik appeared calm and spoke only to say, “Not guilty, your honor,” and answer a few personal questions. He was ordered to surrender his passport and any firearms, and to have no contact with potential witnesses. He was to be released on $500,000 bond, secured by his home in New Jersey.

Mr. Giuliani appointed Mr. Kerik police commissioner in 2000 and endorsed his 2004 nomination to head the Department of Homeland Security. Days after President Bush introduced Mr. Kerik as his nominee, however, Mr. Kerik announced he was withdrawing his name because of tax issues involving his former nanny.

Prosecutors had been presenting evidence to a federal grand jury for several months.

The investigation of Mr. Kerik, 52, arose from allegations that, while a city official, he accepted $165,000 in renovations to his Bronx apartment, paid for by a mob-connected construction company that sought his help in winning city contracts.

U.S. Attorney Michael J. Garcia said some of the payments detailed in the indictment took place after Mr. Kerik became police commissioner.

“During the time that Kerik secretly accepted these payments, he lobbied city officials on behalf of his benefactors — in effect selling his office in violation of his duty to the people of this city,” Mr. Garcia said.

The head of the criminal division of the New York FBI office, David Cardona, noted that the public considers “a beat cop accepting a free cup of coffee” improper.

“If a free cup of coffee is wrong, Kerik’s long list of alleged crimes is repugnant,” he said.

If convicted, Mr. Kerik could face up to 142 years in prison and $4.75 million in penalties.

Mr. Kerik pleaded guilty last year to a misdemeanor charge in state court, admitting that the renovations constituted an illegal gift from the construction firm. The plea spared him jail time and preserved his career as a security consultant, but his troubles resurfaced when federal authorities convened their own grand jury to investigate allegations that he failed to report as income tens of thousands of dollars in services from his friends and supporters.

Mr. Kerik’s efforts in response to the September 11, 2001 attacks helped burnish a career that came close to a Cabinet post.

Mr. Giuliani frequently says he made a mistake in recommending Mr. Kerik to be Homeland Security chief, but that might not be enough to avoid the political damage of a drawn-out criminal case involving his one-time protege.

During a campaign stop yesterday in Dubuque, Iowa, Mr. Giuliani was asked whether he still stood by Mr. Kerik. He sidestepped that question and said the issue had to be decided by the courts.

“A lot of public comment about it is inconsistent with its getting resolved in the right way in the courts,” Mr. Giuliani said.