ATLANTA — United Airlines parent UAL Corp. and US Airways are holding talks on a merger that would create the second-largest U.S. carrier, two people familiar with the matter said.

Discussions have been under way since about mid-February, said one of the people, who asked not to be identified because the negotiations are private. The tie-up would help United steer travelers to its international flights from US Airways’ domestic routes, the person said. Airline spokesmen declined to comment.

Combining United, the third-biggest U.S. carrier, with sixth-largest US Airways would reshape the industry. The merged airline would trail only Delta Air Lines in traffic and would pressure second-place American Airlines. Wider route networks help airlines to funnel in more passengers.

The talks revive a merger effort that collapsed in 2008, less than two months after Delta agreed to acquire Northwest Airlines. Chicago-based United said at the time it would pursue an alliance with Continental Airlines Inc.

United Chief Executive Officer Glenn Tilton and US Airways CEO Doug Parker have both championed consolidation. Tilton said in a Jan. 21 interview that global alliances were smoothing the path toward mergers, while Tempe, Ariz.-based US Airways made a hostile bid for Delta in 2006.

UAL climbed $1.50, or 7.9 percent, to $20.45 at 7:06 p.m. in New York on the Nasdaq Stock Market, while US Airways jumped $1.41, or 21 percent, to $8.23. The talks were reported by the New York Times after the close of regular trading.

“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.”

James Olson, a US Airways spokesman, also declined to comment.

United operates U.S. hubs in Chicago, Denver and San Francisco and at Washington’s Dulles airport.

US Airways’ hubs are in Phoenix, Philadelphia and Charlotte, N.C.