Delta extends American Express SkyMiles agreement

Delta Air Lines is extending an agreement with American Express for its Delta SkyMiles credit card.

Delta closed its acquisition of Northwest Airlines in October, with the combined airline carrying the name of Delta.

The new American Express agreement means Northwest’s WorldPerks credit card, issued by U.S. Bank, will end late next year, and those customers can transition to the Delta American Express card if they want to have a Delta frequent flier card.

Delta said it will get a $1 billion boost from American Express’s purchase of SkyMiles through the pact, and the airline expects to get another $1 billion via contract improvements through 2010.

Delta plans to merge Northwest WorldPerks with SkyMiles in late 2009, and expects SkyMiles will become the largest airline loyalty program, with 74 million members. When the two programs are integrated WorldPerks miles will be transferred in full to Delta SkyMiles, and until then WorldPerks cardholders can continue to earn WorldPerks miles.