http://money.cnn.com/2011/02/15/news/companies/delta_skymiles/ NEW YORK (CNNMoney) -- Delta Air Lines said Tuesday that it has gotten rid of expirations for its SkyMiles program. Under the previous SkyMiles system, miles expired after 24 months if there wasn't any qualifying mileage activity during that time, such as the earning or redeeming of miles. But as of Jan. 1, the system of expiration has ended, according to Delta, and SkyMiles will not expire for lack of activity. "We know how much customers value their miles, so eliminating mileage expiration is a major win for them," said Jeff Robertson, vice president of Delta's SkyMiles division. Delta (DAL, Fortune 500), which recently acquired Northwest Airlines, and Continental, which has merged with UAL Corp.'s (UAL) United, are both airlines that do not allow miles to expire on their mileage programs.