In the United States, Boeing owns the 737 MAX, a plane that crashed last month near the Caribbean island of Barbados.
In a statement to CNNMoney, Boeing said the plane was a test aircraft that was not in service at the time.
“Boeing has been working with the authorities to investigate the cause of the crash,” the company said.
The plane is being sold to an individual who was not named in the statement.
The airline has yet to identify the owner of the plane, CNN said.
The plane was owned by U.S. Airways, which is headquartered in Louisville, Kentucky.
Boeinger has been in the U.K. since 2013, when it bought a majority stake in British Airways, the biggest domestic airline in the world.
“The crash at Barbados was a tragic loss for the aviation industry and the passengers and crew of our aircraft,” U.N. Secretary-General Antonio Guterres said in a statement.