The airline's parent company, AMR Corp., filed for bankruptcy in January and put the home on the market in August, the Los Angeles Times reported Friday.
Now the firm has filed papers in bankruptcy court that list CG Properties Nominees Ltd. as the buyer of the Kensington district house.
The court has scheduled a hearing for Jan. 9 to review the sale, the Times said.
"We cannot help but wonder why the company waited so long to sell the 5,200 sq. ft. luxury home," the Association of Flight Attendants wrote in an online posting.
The union had been critical of the airline owning the property in the past. Criticism included accusations the airline had held onto the home through the summer so executives would have a place to stay during the Wimbledon tennis tournament.
The company declined to comment on the union's barb. Airline spokesman Sean Collins said selling the home would "enable American to realize immediate funds that will increase the pool of assets available for our creditors."