Boeing Co. is close to securing a major order for Emirates Airline's 777X wide-body jetliner, according to people familiar with the matter, which will provide a major boost to a program that is years behind schedule. People familiar with the matter said that Emirates is already the largest buyer of this wide-body aircraft and is preparing to order double-digit quantities of 777X. spoke on condition of anonymity to discuss private negotiations. Regional unit FlyDubai may take delivery of some of the smaller 787 Dreamliners as part of the deal, people familiar with the matter said.

A deal with the largest international airline would be an important endorsement of Boeing's newest and largest aircraft, which has struggled to drum up sales as it remains behind schedule to enter service.

The Dubai-based airline is one of the largest operators of wide-body aircraft, using its hub in Dubai as a global airport connecting the United States, Europe and Asia. As the Dubai Air Show kicks off on Monday, the event will provide a backdrop for major deals as airlines rush to replenish and upgrade their fleets.

People familiar with the matter said earlier that other operators likely to announce major commitments at the event include Turkish Airlines, which is close to ordering about 350 Airbus SE aircraft, including narrow-body and wide-body jets.