American Airlines said Friday it has begun to wind down its Northeast Alliance with JetBlue Airways after a U.S. judge's order in May that it end the agreement.

JetBlue said last week it would terminate the three-year-old alliance, which allowed the two carriers to coordinate flights and pool revenue, and not appeal a ruling.

American Airlines said Friday "codeshare flights between American and JetBlue will no longer be available for sale starting July 21." Customers have through July 20 to update any existing American Airlines booking with a JetBlue frequent flyer member number or an existing JetBlue booking with an American Airlines frequent flyer number.

(Reporting by David Shepardson)