Blackberry phone maker Research in Motion kept the number one spot, with a 36% smartphone market share.

Google Android phones accounted for 28% of sales and iPhones for 21% in the first three months of the year.

The leading brand shake-up is the latest sign of increasing competition in the fast-growing market for smartphones, which allow users to browse the web, send emails and run specialised applications.

Last month, Hewlett-Packard Co announced it would pay £800m to acquire Palm, which sells two smartphone models based on its WebOS operating system.

Microsoft, whose Windows operating system is used in the majority of the world's PCs, unveiled a pair of smartphones last month and recently launched a revamped version of its mobile operating system.