Southwest Airlines closed its $1.4 billion acquisition of AirTran Airways on Monday in a deal that will eventually bring the Dallas-based carrier to Atlanta for the first time .

The deal between Dallas-based Southwest and Orlando-based AirTran, announced last September,  will spell the end of AirTran as its operations are gradually folded into Southwest. Executives signed the papers Monday morning in Dallas to close the transaction.

Not much will change for travelers immediately. AirTran will continue to be sell its flights through the AirTran website and will continue to operate its regular flight schedule. Southwest will operate its AirTran subsidiary as a separate airline until it secures a single operating certificate from the Federal Aviation Administration, expected next year.

AirTran has its largest hub at Hartsfield-Jackson, where it is the second-largest carrier behind Delta Air Lines. Southwest's entry into Hartsfield-Jackson through the acquisition is expected to have the biggest competitive impact on Atlanta-based Delta.

Southwest is expected to eventually eliminate AirTran's baggage fees to align it with Southwest's free checked bags policy, for instance, but that won't happen until sometime later.

Southwest and AirTran are marking the close of the deal Monday with employee celebrations in Dallas, Atlanta and other cities where Southwest and AirTran operate.