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The move comes as the three companies try to keep pace in the intensely competitive smartphone market, which this week will see Apple Inc roll out its much anticipated iPhone 4 on five continents. Verizon Wireless, the biggest U.S. mobile provider, said the Droid X phone will go on sale July 15 for $199.99 after a $100 rebate to customers signing a two-year contract.

The Droid X has a 4.3 inch touch-screen and an 8 megapixel camera, according to Verizon Wireless, which already depends on Motorola's Android phones as a key weapon in competing against AT&T Inc, the exclusive U.S. provider for iPhone.