Research in Motion's popular Blackberry mobile device has been the undisputed market leader since its start, however the company now faces challenges as rivals offer similar devices, a new report indicates.

Several BlackBerry clones have previously attempted to challenge RIM's reign in the enterprise market, but this is a more formidable strike, says Sean Ryan, research analyst for IDC's Mobile Markets. The timing is right for a more powerful attack against RIM's BlackBerry as competitive forces converge.

Market researchers from IDC believe that Microsoft's involvement with Motorola and Palm will threaten to weaken RIM's stronghold in the enterprise market. The companies have begun using Microsoft operating systems on its devices, as well as Microsoft backend server software. The study indicates Windows Mobile-supported devices to undergo the fastest growth of any device, comprising 32.3% of the market share by 2010.

Nokia and Motorola are in strong positions as well because of their leadership in the overall mobile phone market, the firm stated, giving them influence as well as key positions within the value chains to challenge the work of RIM.

IDC expects enterprise converged mobile device shipments to reach 63 million units worldwide by 2010, up from 7.3 million in 2005. RIM currently has 5.5 million subscribers worldwide, and over $2billion in sales this for 2006.