Atlantic Southeast Airlines is now the new ExpressJet Airlines. The new ExpressJet Airlines was created in November 2011 when ... the Atlantic Southeast and ExpressJet merger was approved for single operating certificate status by the FAA, and the two airlines began operating as one. Headquartered in Atlanta, the new ExpressJet is the world’s largest regional airline with 10,000 aviation professionals, an average of 2,200 daily flights and an all-jet fleet of more than 400 aircraft. Through capacity purchase agreements, it operates as Delta Connection and United Express to serve more than 185 airports in 41 U.S. states, Bahamas, Caribbean, Canada and Mexico. read more