(Reuters) - Train maker Alstom has signed a seven-year contract extension for the operations and maintenance of its AirTrains at the John F. Kennedy airport in New York, the French group said on Tuesday.

The contract extension with the Port Authority of New York and New Jersey (PANYNJ) is valued at around $518 million and includes an option for three additional years, the maker of France's TGV high-speed trains said in a press release.