NEW YORK — A man climbed part way up The New York Times' 52-story headquarters early Wednesday, becoming the third person to scale the futuristic skyscraper in less than five weeks.

The climber, identified by the Times as David Malone, made it to the 11th floor of the building in midtown Manhattan before descending to a lower floor and spending hours making cell phone calls and talking to police. He was arrested about 5:30 a.m., police said.

Police said the climber was taken to Bellevue Hospital Center for evaluation; charges were pending.

At one point, the climber unfurled a banner on the "T" of the Times' sign on its building that referred to Osama bin Laden, the Times reported on its Web site. Malone is the author of a book, "Bin Laden's Plan," that argues that Sept. 11 was part of a plot by al-Qaida to provoke the U.S. into invading Iraq, according to a summary on the bookseller site.

On June 5, daredevil Alain Robert and Renaldo Clarke separately climbed the Times building, which the newspaper company moved into last year. It is covered with slats that allowed the men to climb the tower like a ladder.

Dozens of police and firefighters responded about 1:30 a.m. after the new climber was first spotted on the building, police said. Streets were closed off and an inflatable cushion was placed in front of the main entrance.

The Daily News reported on its Web site that it had received a call from a man identifying himself as Malone. He said he was a 29-year-old college dropout from Connecticut who had studied al-Qaida for years. He said he wanted to draw attention to his belief that al-Qaida's "intentional provocation of the U.S." was the greatest threat to American national security.

Police did not immediately confirm those reports.

On June 5, both climbers made it to the top and were charged with reckless endangerment, criminal trespass and disorderly conduct. Malone told the News that the Times itself provided information about how to scale its new headquarters in an article about the June climbs.

A spokeswoman for the Times, Catherine Mathis, said modifications were made to the building and additional security was added after those stunts. The company was investigating how Wednesday's climber was able to overcome the additional obstacles.

The criminal case against Robert evaporated when grand jurors refused to indict him after hearing about his climbing experience and safeguards. He still faced a disorderly conduct citation, a far less serious charge.

After the grand jury refused to indict Robert, prosecutors said they were weighing how to proceed against Clarke.