Shares in BlackBerry maker Research In Motion (RIMM) fell 15.4% to $70.26 after the company disappointed the Street with its second-quarter revenue and third-quarter forecasts.

Intense competition from Apple Inc. (AAPL), Motorola Inc. (MOT) and Palm Inc. (PALM) and higher sales of lower-cost BlackBerry models were among the drivers analysts cited as they digested the revenue miss. Some suggested the stock had run and may have gotten ahead of earnings.

Of particular interest, the company said after the market closed on Thursday that it expects the average selling price of a BlackBerry to drop to about $320, or more than $20 below some analysts' estimates.

But the Street's forward-looking predictions were divided Friday. Some said the smartphone maker is likely to cede market share and face earnings challenges. Others called Friday's dip in shares a buying opportunity.

As it cut its rating on the stock to neutral from conviction buy, Goldman Sachs said the failure of the company's new Javelin and Tour products to match previous launches' subscriber growth "makes us doubt RIM's ability" to maintain its North American smart-phone market share.

The firm also said the second consecutive decline in international sales "tempers our expectations for share gains overseas," and noted the shares have tripled since mid-2006, when the firm first issued its buy rating.

Deutsche Securities warned of "trouble ahead" as it cut the stock from hold to sell, citing mounting competition and weak cashflow.

But Citigroup, which rates the shares a buy, said the new Storm 2 launch in November should help raise the average selling price.

Citi said it viewed the slide in shares as "an overreaction which creates an opportunity."

Bank of America-Merrill Lynch analysts said that the company's market share is now coming at expense of prices and sales growth, and that the low handset average selling price implies a $300 million sales miss.

But it kept its buy rating on the shares. "We would accumulate on weakness," the analysts wrote.

Officials at Research In Motion could not be immediately reached for comment.

-By Brendan Conway, Dow Jones Newswires; (212) 416-2670; brendan.conway@dowjones.com