US-based aircraft manufacturer Boeing has delivered three 777s, two 777-ERs and one 777 freighter to Dubai-based Emirates airline.

The latest aircraft deliveries, made on 3 September, bring Emirates’ current in-service fleet to 237 and its total Boeing 777 fleet to 150. These also bring the carrier’s on-order aircrafts from Boeing to 196.

The deliveries make Emirates the largest operator of the 777, the only airline to operate all six of the 777 variants, and the only customer in 15 years to receive three 777s at one time, according to a statement released jointly by both firms today.

Emirates is understood to have ordered its first Boeing 777s in 1992, with delivery beginning in 1996. It made news during the 2011 Dubai Airshow, when it made an order for 50 777-ERs, and yet another 150 777s at the show’s 2013 edition.

The 777-300ER comprises the largest part of Emirates’ fleet. The aircraft model gained popularity among airlines for its fuel and cost efficiency.

Emirates, Qatar Airways and Abu Dhabi’s Etihad Airways make up some of the largest clients of Boeing. They are also currently involved in a long-drawn open skies dispute with the US Big Three. The Gulf airlines, led by Emirates CEO Tim Clark, have stressed that their US rivals’ request for the US government to review the open skies agreement and freeze the Gulf airlines’ operations in the US market at current levels will do “irreparable harm to America’s world-leading aerospace industry”.