NEW YORK (Bloomberg) — Continental Airlines Inc., after calling off a merger with United Airlines two years ago, would resume consolidation efforts to remain competitive, chief executive officer Jeff Smisek said.

Continental, the fourth-largest US carrier, will keep monitoring the progress of Delta Air Lines Inc. following its 2008 merger with Northwest Airlines Corp., he said yesterday at a JPMorgan Chase & Co. aviation conference in New York. Continental's decision to avoid joining UAL Corp.'s United in April 2008 was correct at the time, he said.

"We'll continue to watch competitive dynamics," Smisek said. "If we think it's in our best interest to bulk up defensively, we'll do so. But I think it's premature to make that decision at this time."

United CEO Glenn Tilton said in January that a merger involving US carriers would be likely in 12 to 24 months, and that the path toward combinations is being smoothed by global alliances. Tilton has advocated US airline industry consolidation since at least 2004.

Continental joined United in the Star alliance of carriers last year and the two US airlines are part of a joint venture with Deutsche Lufthansa AG and Air Canada across the Atlantic. Continental and United have asked regulators for permission to combine flight schedules and fares across the Pacific with All Nippon Airways Co., their partner in Star.

"We're finding great results in the Star alliance," Smisek said. The carrier left the SkyTeam group of carriers, which includes Delta and Alitalia SpA, to join Star. "That's been a home run for us."

The airline, based in Houston, is carrying about 2.5 more passengers per seat with its Star partners than it did with SkyTeam, he said.

Continental shares have climbed 15 percent this year.