Apple could reveal the next version of its mobile operating system at the beginning of June in San Francisco.

The Moscone Center is a popular venue for Apple events and has been booked for a week starting on 11 June. The firm traditionally holds its Worldwide Developers Conference (WWDC) at the beginning of June.

To disguise and not give away the event ahead of Apple’s announcement the Moscone website has it listed as a ‘corporate meeting’. The WWDC is typically used to show off new versions of Apple’s OS X and iOS operating systems before launch.

Last year at the conference, Apple announced iOS 5 but held off revealing the iPhone 4S until October.  It’s unclear whether it will stick to this routine again or decide to unveil the iPhone 5 at the show along with iOS 6.

This month Apple launched its third generation iPad. It has been on sale for a week and sold around 3 million units in its first three days on sale. See also: New iPad review.