A settlement was reached in Cantor Fitzgerald's September 11 lawsuit against American Airlines.
The financial services firm lost 658 employees in the attacks.
The settlement with the airline and insurance carriers is worth $135 million.
The firm sued American Airlines for negligence because its Flight 11 crashed into the North Tower of the World Trade Center.
The settlement avoids a trial that was scheduled for January and closes the chapter on nine years of litigation resulting from the terrorist attacks.
The settlement still has to be formally approved by the judge in a hearing next month.