The merger between Northwest Airlines and Delta Air Lines, and the largest merger since American Airlines acquired TWA in 2001, has been approved by the airlines’ shareholders and received regulatory approval from the European Union. One of the final hurdles–approval by the federal antitrust review board–occurred at the end of October.

Members of Northwest WorldPerks concerned about their miles can be reassured by a statement from Bob Soukup, Managing Director WorldPerks. He wrote in an email to InsideFlyer, “Eventually, WorldPerks will merge with SkyMiles into one single program, but there is no danger to miles. They will be valid on the combined entity. The integration of the two programs will not happen until mid/late in 2009 but the programs will become more and more synchronized after the merger.”

Although there is still a lot of work to do to combine the two airlines, elite members of Delta SkyMiles and Northwest WorldPerks are now eligible to receive complimentary upgrades on Delta and Northwest flights. The reciprocal upgrade benefit will not be extended to companions. SkyMiles companions will only receive upgrades on DL coded and Delta operated flights and WorldPerks companions will only receive upgrades on NW coded and Northwest operated flights. SkyMiles and WorldPerks Platinum, Gold and Silver members will receive upgrades based on member status and booking class when flying eligible flights operated by Delta, Delta Connection, Delta Shuttle, Northwest or Northwest AirLink (Mesaba, Compass and Pinnacle). Elite members of both programs will also receive waived baggage fees on Delta and Northwest operated flights.