A federal jury ruled Monday that the Sept. 11 attack on the World Trade Center (search) was two occurrences for insurance purposes, meaning leaseholder Larry Silverstein (search) stands to collect up to $4.6 billion.

The verdict in U.S. District Court in Manhattan was the latest twist in Silverstein's efforts to double his $3.5 billion insurance policy on the trade center complex.

Silverstein lost a first trial on the issue earlier this year, but a separate jury said Monday that Silverstein is entitled to collect a double payout for nine insurers who covered him for $1.1 billion.

The verdict means Silverstein could ultimately collect $4.6 billion for the Sept. 11 attacks, lawyers in the case said.

Silverstein still must go to a three-person appraisal panel to collect the money. The insurers are also expected to appeal the decision.

In a statement, Silverstein said he was thrilled with the verdict and cast it as a victory for all New Yorkers because it secures additional money to rebuild the trade center complex.

"I strongly felt, and the jury agreed, that the destruction of the twin towers by two separate airplanes at two separate times was two separate occurrences and that these insurers have an obligation to pay their fair share to help make Lower Manhattan whole again," he said.

Regardless of the insurance payout, Silverstein and redevelopment officials have promised to rebuild the trade center complex in the next decade, including 10 million square feet of office space, a memorial and cultural buildings.

The insurance companies involved in the case were: Travelers Indemnity Co., Industrial Risk Insurers, Royal Indemnity Co., Allianz Insurance Co., Tokio Marine and Fire Insurance Co., Twin City Fire Insurance Co., Tig Insurance Co., Westfield WTC LLC and Zurich American Insurance Co.

In her closing argument, lawyer Carolyn H. Williams argued on behalf of the companies that the hijacked planes were like guided missiles and that the insurance payout should not depend on whether terrorists used "one or two or 10 or 100 weapons."

On behalf of Silverstein, attorney Bernard Nussbaum said there was precedent in the insurance industry to find the terrorism was two events. A California case concluded that four separate insurance events occurred when an arsonist set four separate fires, including two six minutes apart in courthouses 200 yards apart.