Verizon Wireless said it will start selling the high-speed Bionic phone from Motorola Mobility on Sept 8, months after the device had been expected to launch.

The companies said the Bionic, which was originally slated to go on sale in the second quarter, will cost $299.99 to customers who opt for a two-year contract.

The Bionic is based on Google Inc's Android software and is Motorola's first phone to support a high-speed network Verizon Wireless is building based on new technology known as Long Term Evolution.

Motorola, which has lost ground to rivals such as Samsung Electronics Co Ltd <005930.KS> and HTC Corp <2498.TW> because of the delay, had warned in July that a delay until September would hurt its third quarter results.

Motorola agreed last month to be bought by Google for $12.5 billion. Verizon Wireless is a venture of Verizon Communications and Vodafone Group Plc .

(Reporting by Sinead Carew; editing by Derek Caney)