Pennsylvania's attorney general has joined counterparts in 18 states in a U.S. Justice Department review of the proposed merger between US Airways Group Inc. and American Airlines.

Joe Peters, spokesman for Attorney General Kathleen Kane, confirmed that Pennsylvania is among the states reviewing the effect of the merger on competition and air service. "As with all such cases, our review is intended to ensure that the consumers' interests are protected," Peters said.

It's not unusual for states to join such reviews. The same thing happened before the 2008 merger of Delta and Northwest airlines and the 2010 merger of United and Continental airlines. Some states have expressed concern that if the Justice Department makes the combined American-US Airways divest takeoff and landing slots at Reagan National Airport in Washington, flights will be cut between the nation's capital and smaller communities.

Both airlines declined to comment. US Airways shareholders will vote July 12 on the merger. The judge overseeing American's Chapter 11 bankruptcy case set a Aug. 15 hearing on American's reorganization plan. American and US Airways announced Feb. 14 their intention to merge. The deal, which would create the world's largest airline, is expected to close by Sept. 30, pending regulatory approval. - Linda Loyd