History suggests American-U.S. Airways merger would quickly gain U.S. approval

U.S. antitrust authorities over the past year have been particularly active, blocking acquisitions in industries from beer to e-books. But the potential deal to create the world's biggest airline likely would fly clear of government objections, experts said.

American Airlines parent AMR Corp. and US Airways Group Inc. are in final negotiations on a marriage that could be announced as early as this week.

But the deal involves only about a dozen overlapping routes, similar to the number in the most recent three big airline mergers, according to research by J.P. Morgan. Those transactions were cleared by the Justice Department, with the carriers in only one deal required to relinquish takeoff and landing slots to maintain competition.