A mistake on Apple's online store on Wednesday has added more fuel to speculation that the company's latest Mac operating system, codenamed Snow Leopard, is due for launch as early as next week.

The company was offering to ship the as-yet-unreleased Mac OS X 10.6 - codenamed Snow Leopard - within 24 hours as part of the new Mac Box Set products, which were briefly put on sale on Apple's website.

However, the Box Set products were pulled after a call was made to Apple online sales to check whether the new OS would ship in 24 hours as part of the single-user Box Set edition. The Box Set - which also comes in a family pack edition - offers a plethora of software upgrades to Mac users, including the OS, productivity suites and multimedia applications.

A saleswoman verified that the Box Set was for sale online after checking with technical support. But she said that it might not ship overnight as the Snow Leopard OS was not yet shipping.

The saleswoman could not be reached for comment after the products were pulled, and Apple officials did not return calls or email for comment.

The online store glitch could give credence to reports that Apple is preparing for an early launch of Snow Leopard, which is officially scheduled to go on sale in September. Observers, including analysts and blog sites, have predicted the OS would start to ship as soon as 28 August.

Retail sites like Amazon.com are already taking pre-orders for Snow Leopard and the Mac Box Set. Snow Leopard is available as an upgrade to Mac OS X version 10.5 Leopard users for $29.99 (£18.80).

The OS includes a number of systemwide "refinements," according to Apple's website. The enhancements include quicker installation compared to predecessors, a new version of QuickTime multimedia software and a souped-up user interface. It also includes a number of internal enhancements to perform tasks like video encoding and decoding faster by tapping into the processing power of multiple CPU and graphics processing cores.