Shares of Research In Motion ( RIMM) were rising in morning trading after the company was upgraded by Lehman Brothers, thanks to an expected rise in the wireless Blackberry subscriber base.

Recently the stock was up $1.65, or 9%, to $20.10 on the news.

The brokerage firm upgraded the company's stock to overweight from equal weight after management said it expects Blackberry subscribers to reach more than 1 million in the next year.

Currently, Research In Motion has 354,000 subscribers. U.S. carriers such as Nextel ( NXTL), AT&T Wireless ( AWE) and T-Mobile also indicate that they're starting to beef up subscriber counts and that Blackberry sales are "a centerpiece of the companies efforts in enterprise data," Lehman said.

The firm raised its year-end 2004 subscriber forecast for Research In Motion to 869,000, from a prior estimate of 843,000. By February 2005, Lehman sees 1.3 million subscribers.

Lehman also upped its financial estimates for the company, saying it expects Research In Motion to break even in the fourth quarter 2004 with about $118 million in sales. Total revenue estimates were raised to $425 million from $400 million for 2004 and to $530 million from $490 million for 2005.

The firm expects Research In Motion to post a loss of 21 cents in 2004, compared with a prior expectation of a loss of 25 cents, and Lehman is looking for earnings of 30 cents a share in 2005, raised from 15 cents a share expected previously. Research In Motion's target price was also lifted to $22 from $18.

The brokerage firm said that 2002 was a hard year for the company due to limited subscriber growth, even after higher spending on new carrier partners. Higher-than-expected expenses and slower-than-expected revenue growth also hurt the company.

But Lehman concluded that "Research in Motion appears firmly established as the leading player in wireless messaging, which is one of the most exciting near-term mobile data applications."