Air New Zealand is to put Boeing 777-300ER twinjets into service under 330min extended operations, after the airframer secured type design approval for the increase.
The approval covers 777 variants fitted with General Electric GE90 engines, and includes the 777-200LR and 777F, which have the powerplant installed as standard, as well as the GE-powered 777-200ER.
But the carrier intends to pursue similar certification for the 777-200ER, fitted with Rolls-Royce Trent 800 as well as Pratt & Whitney PW4000 engines.
Clearance from the US Federal Aviation Administration for these powerplants "is expected to follow over the next few months", the carrier added.
Boeing has looked at 330min extended twin-engine operations (ETOPS) certification for the 777-300ER for several years, having flown an initial 330min engine-out demonstration on a Seattle-Taipei test flight in 2003.
That flight, part of the 777-300ER's certification programme, involved the crew's shutting down one of the GE90s and flying on a single engine - at the time the longest such flight the airframer had conducted.
Air New Zealand is the first carrier to purchase the new ETOPS option. The airline has already performed 240min ETOPS flights between Los Angeles and Auckland.
Extension of the ETOPS capability will provide greater route flexibility to carriers in the South Pacific, those flying transpolar tracks and operators carrying out intercontinental services in the southern hemisphere.
"The airplane is able to fly a straighter route between the city pairs, and that's good for the environment," said Air New Zealand chief pilot David Morgan. "It's also good for customers because flights are potentially shorter and passengers could arrive sooner at their destinations."