NEW YORK – Jury selection starts today in Round 2 of World Trade Center leaseholder Larry Silverstein’s attempt to increase his $3.5 billion insurance payout.

Mr. Silverstein suffered a blow in Manhattan federal court earlier this year when a jury ruled that the two planes hitting the twin towers on September 11, 2001, constituted one event under contract language that affected 13 insurers.

If Mr. Silverstein’s lawyers can convince jurors in the second trial that the attack was two occurrences, he will stand to collect $1.1 billion more from nine insurers involved in this phase. Opening statements are scheduled for October 18.

Mr. Silverstein has vowed to rebuild 10 million square feet of office space at ground zero regardless of how much money he collects from insurers. He and redevelopment officials plan to construct the 1,776-foot Freedom Tower, other skyscrapers, and cultural buildings within the next decade.

Mr. Silverstein, who holds a 99-year lease on the property, argued in the first trial that he should receive $7 billion, or twice the $3.5 billion insurance policy on the trade center, because the two planes that flew into the towers 16 minutes apart represented two events.

The first trial, which ended in May, focused on whether 13 insurers that provided the bulk of the trade center’s coverage were bound by a brokers contract known as the Wilprop form. But the second trial may include more evidence about what actually occurred on September 11.

In a September 23 pretrial hearing before U.S. District Judge Michael Mukasey, Mr. Silverstein’s lawyers said they would call structural engineer Matthys Levy, co-author of the book “Why Buildings Fall Down: How Structures Fail,” to testify about the sequence of events that caused the towers to fall.

The judge said Mr. Silverstein’s lawyers would not be permitted to show the jurors any photos from September 11 or to put on “a sound and light show” to try to influence them.

During a second hearing on October 1, Katherine Colinvaux, an attorney for insurer Allianz Global Risk, indicated that lawyers for the insurers might put into evidence portions of the September 11 commission’s report to show that the attack was part of a single plot.

She said the lawyers would argue “that the coordinated terrorist attack was not just three words. It was something that was real.”

Mr. Silverstein, who could not be reached for comment by telephone yesterday because of the holiday, has said he plans to appeal the first verdict and is confident of victory in the second trial. The judge has instructed the lawyers involved in the case not to talk to the press.