Apple has unveiled a new MacBook Air, with better battery and Haswell processors, and has announced the pricing and availability.

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. See: MacBook Air (2013) review.

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.

More details to follow.

More from WWDC 2013:

Apple launches brand new, redesigned Mac Pro

Five reasons why Mac OS X 10.9 Mavericks isn't named after a big cat

Apple launches new MacBook Air with battery improvements, Haswell

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