Combining United, the third-largest US carrier, with number six US Airways would create an airline with an extensive route network. United has hubs in Chicago, Denver, San Francisco, and at Washington Dulles International Airport, while US Airways has hubs in Philadelphia, Phoenix, and Charlotte, N.C. US Airways and United Airlines are the fourth- and fifth-biggest carriers, respectively, in terms of passengers, with a combined 25 percent of the market at Logan.
A combination of the two airlines could unseat JetBlue, which is currently the top carrier at Logan, with nearly 18 percent of the market.
US Airways plans to shut down its Boston crew base next month and reduce the number of flights from Logan to the Caribbean. Still, a merger would probably make the combined airline the number one player at Logan, said Daniel Kasper, head of the transportation practice at the Cambridge office of LECG, an economic and financial consulting firm.
US Airways and United do not have many overlapping routes out of Boston, which means there probably would not be a lot of routes cut, or prices raised, if the two merge.
United flies mainly west from Logan — to Chicago, Denver, San Francisco, and Los Angeles, as well as to Washington, D.C. US Airways flies mostly along the East Coast — to Philadelphia, New York, Washington, D.C., and Charlotte, as well as to Phoenix and the Caribbean.
A route that could face cuts is Boston-to-Washington, D.C., which might affect business travelers. But a United-US Airways combined carrier would not want to give up much ground at Logan, particularly given all the gains that low-cost carriers have made recently.
“They would very much like to be able to defend their turf a little bit more effectively,’’ Kasper said.
The Massachusetts Port Authority, which runs Logan, declined to comment, as did US Airways.
“We don’t comment on rumors or speculation,’’ said Jean Medina, a spokeswoman for United. “We’ve been consistent on our position on consolidation generally for several years, and that position is well known.’’