U.S. District Judge Alvin Hellerstein ordered the terms kept secret, the New York Post reported.
The company is negotiating with another 64 families, the Post said.
The plaintiffs include the families of passengers and crew on board the two hijacked American planes and a few families of people killed in the buildings.
By deciding to sue, the plaintiffs opted out of the Victims' Compensation Fund, which was created by Congress to reduce the number of lawsuits.
Hellerstein urged a speedy end to the litigation.
"These are just not dry negotiations," he said. "Lives with extraordinary potential have been wiped out. And I think the process reminds people of what they lost. It is less of what they gained and more of what they lost."
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