Apple has updated its MacBook Air lineup, unveiling the new models at its WWDC 2013 keynote on 10 June.

Apple's senior vice president of Worldwide Marketing Phil Schiller took to the stage to unveil the new MacBook Air. "In this age of the iPad, what is the future of the notebook? The MacBook Air really gave us a direction," he said. See: MacBook Air (2013) review.

Based on the new fourth-generation Intel Core Haswell processor - the replacement for Intel's Ivy Bridge - the new MacBook Air models feature longer battery life, improved wireless network and energy efficiency improvements.

Apple claims that the 11in MacBook Air has been improved from a five hour battery life to a nine hour battery life, while the 13in model goes from seven hours to 12 hours of battery life. Schiller highlighted that you get 10 hours of iTunes move playback with the new MacBook Airs, and you can watch the entire Lord of the Rings trilogy.

The new MacBook Air is designed for power savings, and has a more energy efficient Intel Core i5 and Core i7 CPUs. They have a slower clock speed to save energy, but can still deliver 40 per cent faster graphics performance, says Apple.

There are smarter low-power settings too. You can leave the new MacBook Air on standby for up to thirty days, and it will still wake up in one second, Apple says.

The MacBook Air is based entirely on flash storage, and is up to 45 per cent faster than the previous version.

ther features include dual microphones, a FaceTime HD camera, a high-speed Thunderbolt port and two USB 3.0 ports. The new MacBook Air models also support dual displays and video mirroring alongside full native resolution on the built-in display.

As predicted, the new MacBook Air models are compatible with the 802.11ac wireless networking, which is said to be three times faster than previous standards, but you’ll need an 802.11ac base station. So Apple has launched a new AirPort Extreme that feature three-stream 802.11ac with a maximum data rate of 1.3Gbps, and there’s a new Time Capsule to support the standard as well. The new base station features what Apple calls a beamforming antenna array. Unlike the base station antennas that emit an equal and constant signal in all directions, the beam forming antenna array knows where an 802.11ac devices is on the network and targets the signal to that device.

The new MacBook Air is available today through the Apple Online Store, Apple retail stores and Apple Authorised Resellers.

The 11-inch MacBook Air comes with a 1.3 GHz processor with Turbo Boost speeds up to 2.6 GHz, 4GB of memory and is available with 128GB of flash storage starting at £849, and 256GB of flash storage starting at £1,029.

The 13-inch MacBook Air comes with a 1.3 GHz processor with Turbo Boost speeds up to 2.6 GHz, 4GB of memory and is available with 128GB of flash storage starting at £949, and 256GB of flash storage starting at £1,129.

Configure-to-order options include a 1.7 GHz Intel Core i7 processor with Turbo Boost speeds up to 3.3 GHz, up to 8GB of memory and up to 512GB flash storage.

In the weeks leading up to WWDC 2013, resellers saw a jump in MacBook trade-ins, thanks to widespread speculation that Apple would use this year's WWDC keynote to launch new models of its laptops.

Apple last updated the MacBook Air at WWDC 2012, which turned out to be a successful year for the laptop, with numerous reports stating that the MacBook Air dominated the ultrabook market. See: Ultrabooks disappoint in 2012, MacBook Air is king

Additional reporting from Macworld.com's Jackie Dove.

More from WWDC:

Apple launches brand new, redesigned Mac Pro

New MacBook Air release date and UK pricing

Apple previews OS X Mavericks: tabbed Finder, multiple display support, Maps, Books and more

Apple iOS 7 announced at WWDC 2013

Apple's WWDC 2013 keynote in pictures

New Mac Pro release date, UK pricing