Story highlights Cantor Fitzgerald lost 658 employees in the World Trade Center on 9/11

The brokerage firm sued American Airlines, whose Flight 11 plowed into its offices

The firm and airline settled the $1 billion lawsuit for $135 million

New York brokerage firm Cantor Fitzgerald confirmed Tuesday that it has agreed to settle with American Airlines for $135 million in a lawsuit seeking damages from the September 11, 2001, terrorist attacks.

The settlement was announced on Friday, but the amount was not released until Tuesday.

"For the insurance companies, this was just another case, just another settlement, but not for us," Howard W. Lutnick, Cantor Fitzgerald's chairman and CEO, said in a statement. "We could never, and will never, consider it ordinary. For us, there is no way to describe this compromise with inapt words like ordinary, fair or reasonable. All we can say is that the legal formality of this matter is over."

In 2004, Cantor Fitzgerald filed a lawsuit seeking $1 billion in damages from American Airlines. The firm claimed that American Airlines was negligent by failing to detect the hijackers, permitting them to board and hijack the airplane.

The firm claimed the negligence resulted in business interruption losses and the destruction of its office and corporate property.

Cantor Fitzgerald lost 658 employees when American Airlines Flight 11 crashed into its top-floor offices in the World Trade Center's North Tower.

"American Airlines and the courageous crew members and passengers on Flight 77 and Flight 11 were all victims of the terrorist attacks of September 11, 2001. American has vigorously defended itself in litigation brought against it by property owners and their insurers who allege that American should have done what the government could not do: prevent the terrorist attacks," American Airlines said in a statement.

The settlement still needs to be approved by the judge, which is scheduled for January 13.

"Our insurers have agreed to settle the claims by Cantor Fitzgerald. Although this settlement ends these particular legal disputes, American will forever honor the memory of the true victims and selfless heroes of 9/11," American Airlines said.