MILAN (Reuters) - The multi-year shirt sponsorship agreement between Italy's AS Roma soccer club and Qatar Airways is worth 40 million euros (35 million pounds) for three seasons, a source close to the matter said on Monday.

Earlier AS Roma, who face Liverpool in the Champions League semi-final first leg on Tuesday, said it had signed a deal with Qatar Airways, making the airline the team's official shirt sponsor until 2021.

AS Roma had said that it was the largest deal ever signed by the club and one of the biggest ever agreed by an Italian team.

(Reporting by Elvira Pollina, writing by Giulia Segreti; editing by Paola Arosio)