Research In Motion fell the most in more than six months in Nasdaq trading after saying prices for the BlackBerry handset are dropping, signaling its push into developing countries may hurt profitability.

The average price of a BlackBerry sold to a carrier was $311 last quarter and will drop to between $305 and $310 this quarter, the company said yesterday. RIM projected gross margin, the percentage of sales left after production costs, of 44.5 percent, down from 45.7 percent in the previous period.

Canada-based RIM fell $5.49, or 7.4 percent, to $68.48. The shares have gained 1.4 percent this year.