A couple airlines in the U.S. are combining operations as mergers are nearing completion.

Southwest and AirTran have the green light from the federal government to combine operations.
Thursday the Federal Aviation Administration approved the carriers to operate under a single certificate.
Southwest bought AirTran in 2011. The merger is expecting to take a few years to complete.

Another merger nearing completion is Continental Airlines and United Airlines.

Continental will cease to exist after this weekend as it merges with United. Friday airports began moving Continental branding. The last Continental flight is scheduled to depart from Phoenix shortly before midnight on Friday.

Like AirTran and Southwest, Continental and United will switch over to one system.

United and Continental announced their merger in 2010.