A jury decided that the attacks on the World Trade Center were two separate events for insurance purposes, meaning leaseholder Larry Silverstein can collect up to US$4.6 billion for rebuilding efforts.
The trial boosted Silverstein's potential payout well above the US$3.5 billion for which he had actually insured the trade center but short of the US$7 billion he had once hoped to collect.
Earlier this year, another jury rejected Silverstein's contention that an insurance document defining the attack as one event did not bind some of the 24 insurance companies holding the bulk of the coverage.
The most recent trial was the first in which jurors were asked to decide whether the terrorist attack that killed 2,749 people could be considered two attacks since two planes hit two separate towers.
It involved nine insurance firms that had provided US$1.1 billion of the total insurance package for the trade center. Monday's ruling could double that.
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.
Lawyers for the insurance companies declined to comment.
Regardless of the insurance payout, Silverstein and redevelopment officials have promised to rebuild the trade center complex in the next decade, including 900,000m2 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 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 182m apart.