Apple has launched a new MacBook Air at WWDC that promises all-day battery life thanks to including the new Intel fourth-generation (Haswell) Intel Core processor.

The new processor will give the 11-inch MacBook Air a boost to 9 hours battery life, while the 13-inch model will last for 12 hours on a single charge.

"MacBook Air is the industry leader for thin and light notebooks, and now with longer battery life, we've set the bar even higher," said Philip Schiller, senior VP of worldwide marketing at Apple.

The new MacBook Air 11-inch will start with 128GB of storage and a 1.3GHz processor and 4GB RAM for £849. The new 13-inch MacBook Air will start at the same configuration, and will be available for £949.

The models will retain the existing thin and light aluminium design that's proved popular, along with a Thunderbolt port and 2x USB 3.0 connections.

READ: Apple MacBook Air (2012) vs Apple MacBook Air (2013): What's the difference?

The new models will also get Wi-Fi 802.11ac, faster than the wireless n standard of the previous version. To support the new MacBook Air models, Apple has also launched a new AirPort Extreme router to cope with the new speed.

The new MacBook Air models will start shipping immediately.