Research in Motion late Tuesday warned that it expects the number of new subscribers to its BlackBerry push e-mail service to fall significantly below its original estimates. The Canadian smartphone company now expects to add just 2.6 million users instead of the originally predicted 2.9 million and also expects its earnings per share and gross margins to drop as a result. The company blames the dip both on the later launches of phones like the Bold for AT&T and the multi-carrier release of the Storm.

The news reinforces previous downbeat news for RIM, which in the summer was overtaken by the iPhone despite the BlackBerry range's significantly longer presence in the smartphone market and its lead among business users. New subscriber additions only represent a subset of the total number of BlackBerries sold but reflect the relative growth of the company's overall user base; lower numbers point to more sales skewing towards existing owners than towards converts or first-time owners.

RIM is nonetheless hopeful for the current quarter, which ends in February, and says that it generated a "record level" of daily subscriber additions on the BlackBerry Storm's November 21st launch and has seen similar results in the weeks since the touchscreen model's introduction. RIM believes there is a "growth opportunity" once it ships more products.

The company plans to announce its final results on December 18th.