text: On April 14 , 2008 , Northwest announced it would merge with Delta Air Lines on October 29 , 2008 , making Delta the largest airline in the world .
simplified: On April 14 , 2008 , Northwest announced it will be merging with Delta Air Lines , subject to regulatory review . If approved , the new airline will retain only the Delta Air Lines name and brand , and become the largest airline in the world .