The government authority that owned the World Trade Center has tentatively agreed to pay $47.5 million to settle lawsuits by 9,055 people exposed to toxic dust during the aftermath of the 9/11 attacks.

The Port Authority of New York and New Jersey agreed to the deal after months of negotiations with a law partnership representing thousands of laborers, police officers and firefighters who participated in the cleanup of ground zero.

U.S. District Judge Alvin Hellerstein, who is overseeing the litigation, revealed the settlement in an order filed Thursday. He called the deal "fair and reasonable."

The arrangement is still subject to approval by the Port Authority's board, which next meets on Oct. 21.

The money would be added to an earlier settlement of suits filed against New York City that could be worth as much as $712.5 million, if enough plaintiffs agree to sign on, bringing the total pot to about $760 million.

Thousands of the public and private sector workers who moved mountains of rubble at the trade center say their exposure to the thick clouds of ash and pulverized building materials made them sick.

Many have reported respiratory problems similar to asthma. A smaller number have complained of more serious, debilitating respiratory conditions. Others aren't sick now, but worry they may fall ill in the future.

Paul Napoli, a lead lawyer at the firm that negotiated the deal, said in a written statement that he and colleagues at Worby Groner Edelman & Napoli Bern were "elated" by the agreement.

The Port Authority declined to comment.

Under the terms of the deal, the less seriously ill workers, or those not sick currently, would qualify for payments ranging from $2,000 to $3,000. The rest would divide the remainder of the $47.5 million based on the severity of their condition, and the likelihood it is related to World Trade Center dust.

Like the earlier settlement covering the City of New York, the deal is contingent on its widespread acceptance by the thousands of plaintiffs.

At least 80 percent of those with weaker liability claims, and 95 percent of those with stronger claims, would have to say yes for it to take effect.

That standard is slightly looser than one imposed in the larger settlement, which requires a 95 percent opt-in rate among all plaintiffs. Workers have until Nov. 8 to say yes or no to that deal.

Plaintiffs in the suit had argued that the Port Authority, as the owner of the trade center site, was at least partly responsible for ensuring that people working on the cleanup were fitted with filtered masks to protect their lungs.