Two large U.S. wireless carriers plan to launch Motorola Inc. smart phones based on Google Inc.’s Android operating system before the end of the year, according to people familiar with the matter.

The Google-powered phones, which will be carried by Verizon Wireless and T-Mobile USA Inc., are the result of Motorola Co-Chief Executive Sanjay Jha’s efforts in recent months to overhaul the company’s struggling handset division. Motorola is betting heavily on Android to regain traction in the cellphone market.

But the phones will hit the market just as consumers already have a host of cutting-edge devices to choose from, including Apple Inc.’s latest iPhone model and Palm Inc.’s new Pre. Apple on Monday said it sold more than one million units of its new iPhone 3G S model in its first three days on the market, and has sold more than 20 million iPhones since the device’s launch in June 2007.

T-Mobile USA, on Monday announced another Android phone, the myTouch 3G by HTC Corp. of Tawain, which will be available at retail stores in August for $199 with a two-year contract.

A Motorola spokeswoman declined to comment.

T-Mobile USA will launch a touch-screen Motorola phone with a slide-out keyboard, an increasingly popular hardware setup. The software, built on Android, will emphasize “social communications” services, a person familiar with the device said. The phone will have a range of built-in social-networking software from popular providers such as Facebook and Twitter, the person added.

Verizon Wireless, a joint venture of Verizon Communications Inc. and Vodafone Group PLC, is planning to carry a Motorola device with similar hardware to the T-Mobile one, including a touch screen and slide-out keyboard, a person familiar with the situation said.