More than two dozen US insurers affiliated with Travelers Cos have sued two Saudi banks, companies affiliated with Osama bin Laden's family, and several charities for at least $4.2 billion over the September 11, 2001 attacks.
The lawsuit filed late on Wednesday night in the US District Court in Manhattan is the latest effort to hold entities in Saudi Arabia liable for the attacks.
Nearly 3,000 people died when hijacked airplanes crashed into New York's World Trade Center, the Pentagon near Washington, DC and a Pennsylvania field.
The 10 defendants in the lawsuit include Al Rajhi Bank, National Commercial Bank, aviation contractor Dallah Avco, the Mohamed Binladin Co, the Muslim World League, and other charities.
They were accused in the lawsuit of having "aided and abetted" the attacks through a variety of "activities in support of al Qaeda" in the years leading up to them.
"But for the assistance provided by defendants," the lawsuit said, "al Qaeda could not have successfully planned, coordinated, and carried out the September 11th attacks, which were a foreseeable and intended result of their material support and sponsorship of al Qaeda."
The insurers are seeking to recoup sums paid to policyholders who suffered personal, property and business injuries from the attacks.
Their lawsuit seeks at least $1.4 billion of compensatory damages, triple damages and punitive damages.
The defendants could not immediately be reached for comment on Thursday, which is the start of the weekend in the Gulf.
Al Rajhi has previously said that US courts have "repeatedly" dismissed similar claims against the bank, which "has no links to terrorism" and is "committed to operating at the highest levels of compliance" with applicable rules.
The Saudi government and affiliates including the Public Investment Fund, its sovereign wealth fund, have a majority stake in National Commercial Bank.
A Travelers spokesman, Matt Bordonaro, had no immediate additional comment on Thursday.
Several other lawsuits pending in the Manhattan court seek to hold Saudi Arabia liable to individuals and insurers over its alleged involvement in the September 11 attacks. The Saudi government has denied such involvement.