Scott Kirby, chief executive of United Airlines (UA, Chicago O'Hare), has ruled out any possibility of a merger with JetBlue Airways (B6, New York JFK), saying he never hinted at such a move, even when he mooted the possibility of a business combination with American Airlines, which some viewed as a way to alleviate government concerns over a smaller transaction.

Speaking in a question-and-answer session during Bernstein’s 42nd Annual Strategic Decisions Conference, Kirby said: “For many years, the only kind of big transaction that we tried was the only one that made economic sense. None of the other deals [apart from American] made sense.”

He added that any major transaction would require “a willing partner, which we clearly don’t have”. American outright rejected the possibility of a merger with United after the initial reports.

Asked about JetBlue, Kirby said he did not understand why speculation about a merger with the carrier had gained traction. “I never understood why everyone thought we were going to do it. I never said it, never hinted at it,” he explained.

JetBlue, he added, would need to improve its margins by 25 percentage points to make such a deal viable, something that appeared “mathematically close to impossible to me.”

In April, Semafor reported that JetBlue had explored a potential sale to a competitor, citing people familiar with the matter. The airline subsequently denied the reports. United was widely regarded as a potential suitor given the carriers’ existing 'Blue Sky' partnership.