Delta Air Lines has announced that Delta SkyMiles and Northwest WorldPerks members now have the ability to link frequent flyer accounts and transfer miles between both accounts at no charge. Members who link their accounts before March 15, 2009 will earn 500 bonus miles.

This new feature allows current members who have SkyMiles and WorldPerks accounts to visit delta.com or nwa.com, link their accounts and transfer any amount of miles into either account on an unlimited basis. Both accounts will remain open and functioning until late 2009 when Delta plans to merge the two programs to deliver one best-in-class loyalty program for members in 2010.

“The mileage-transfer feature enables our frequent flyer members to immediately enjoy both SkyMiles and WorldPerks redemption opportunities, including Award Tickets, upgrades, merchandise and experiences. We encourage them to link their accounts today,” said Jeff Robertson, Delta’s vice president of Loyalty Programs. “This marks yet another step toward aligning the two programs and offering more value to our combined members.”

The programs recently announced that members may earn elite status by flying a designated number of flight segments on either Delta- or Northwest-operated flights. Additionally, SkyMiles and WorldPerks elite members continue to be eligible for complimentary First Class upgrades on both airlines’ flights.

More information on the SkyMiles program is available at delta.com/skymiles. WorldPerks program information is available at nwa.com/wolrdperks.