The BlackBerry maker Research In Motion Ltd. (RIM) reported 4 percent plunge in the second-quarter profit, as the charges for a patent settlement with Visto Corp. and aggressive competition from Apple Inc.''s iPhone bowed down the sale of BlackBerry devices.

The Waterloo, Ontorio-based Company filed a profit of $475.6 million, or 83 cents a share, for the three months ended August 29, 2009, down from $495.5 million, or 86 cents a share, a year earlier.

The announcement sent the shares of the company tumbling down by more than 11 percent in extended trading.

On an adjusted basis, the company earned $588.4 million, or $1.03 a share, excluding the charge to settle all outstanding worldwide patent litigation with Visto Corp.

Its revenue jumped 37 percent from $2.58 billion in the same quarter of last year to $3.53 billion.

During the quarter, RIM shipped approximately 8.3 million devices. 

Meanwhile, it added about 3.8 million net new BlackBerry subscribers in the quarter, totaling the BlackBerry subscriber account base as approximately 32 million at the end of the quarter.

For the current period, RIM foresees earnings of $1 to $1.08 a share on revenue of $3.60 billion to $3.85 billion.