Boeing will deliver 25 787-8 Dreamliners to United Airlines (UA) under a new $4.2bn contract.

The twin-aisle aircraft will carry 210-250 passengers on routes of 7,650nm to 8,200nm, at a cruise speed of Mach 0.85.

Dreamliners provide greater fuel efficiency and up to 45% more cargo capacity.

The order also includes opportunities for purchase of another 50 Dreamliners.

UA plans to take delivery of the 787s to retire its 747s and 767s operating on international routes.

The Dreamliner recently witnessed a setback to its flight test phase, as the first aircraft faced engine trouble resulting from sensor issues.