McTiernan, who pleaded guilty Monday to making false statements, faces up to five years in prison when he is sentenced July 31.
He is the highest-profile figure yet to plead guilty in the investigation of Pellicano, who is accused of bugging phones and bribing police to get information on celebrities and others. Pellicano has pleaded not guilty.
Asked by U.S. District Judge Dale Fischer on Monday if the statements he made to the FBI agent were false, McTiernan replied: "They were knowingly false, your honor."
McTiernan, director of "The Thomas Crown Affair," "The Last Action Hero" and other films, sketched out a scenario that began with a phone call to his home on Feb. 13 from a person identifying himself as an FBI agent.
He said he told the agent the only time he used Pellicano's services was in his divorce.
"He asked me if I had hired him in any other area, and I said, 'No, I didn't,'" McTiernan told the judge.
Actually, McTiernan added, "I had hired Anthony Pellicano to wiretap Charles Roven in the summer of 2000. ... But I never received a report or specific information."
Roven worked with McTiernan on the 2002 box-office flop "Rollerball." Roven was a credited producer and McTiernan directed and produced the film.
McTiernan said he paid Pellicano $50,000 for the illegal wiretap, and in the end, "I paid him off and fired him."
Assistant U.S. Attorney Dan Saunders asked the judge to seal the plea agreement documents, and he refused to answer questions outside court about whether the government had agreed to make a recommendation for leniency in sentencing.
Fischer allowed McTiernan to remain free on bond until sentencing.
The speed with which McTiernan entered his guilty plea came as a surprise after an arraignment earlier in the day in which his attorney told another judge there was a plea agreement. No details were announced and another hearing was scheduled for next week.
But McTiernan's lawyers sought a speedy resolution, and Fischer, who is presiding over other Pellicano-related cases, agreed to take the case.
Allegations against Pellicano, 62, include tapping the phone of actor Sylvester Stallone and having police run the names of comedians Garry Shandling and Kevin Nealon through a government database.
By Linda Deutsch