[This post has been update]

Baltimore Washington-International Marshall Airport will begin a major expansion of passenger areas over the next two years.

(Charles Dharapak)

BWI also announced that AirTran Airways will move to the Southwest Airlines terminal as the companies begin to consolidate following their recent merger.

Delta Air Lines and AirTran will swap locations.

Ticketing and baggage check-in for AirTran will be located in the Terminal A/B lobby, and all AirTran flights will operate from gates on Concourse B. The changes begin Nov. 16.

To handle the increased traffic, BWI and the Transportation Security Administration have added a new, four-lane security checkpoint near Concourse A. Sixteen automated ticketing kiosks and a third curbside check-in location are also being added.

The airport has added new concessions in Terminal A/B and others are expected to open soon.

Southwest and AirTran completed the deal earlier this year, becoming the Washington region’s dominant carrier. The two companies handle about 32 percent of the area’s air travel. Southwest said in May that integration might not happen until 2012, when AirTran is expected to begin flying under Southwest’s colors.

The deal was originally announced in the fall of 2010. .