NEW YORK (Bloomberg) - Verizon Wireless, the largest US mobile-phone company, will start selling handsets based on Google Inc.'s Android operating system, aiming to challenge AT&T Inc.'s iPhone.

Google and Verizon Wireless will develop several Android devices together that will include programs from both companies, they said yesterday in a statement. Basking Ridge, New Jersey-based Verizon Wireless will introduce Android devices in a few weeks.

Verizon is adding more so-called smart phones to keep pace with AT&T, the exclusive carrier of Apple Inc.'s iPhone, and Sprint Nextel Corp., which offers Palm Inc.'s Pre. Global sales of smart phones, which surf the Web and send e-mail, climbed 27 percent in the second quarter, according to researcher Gartner Inc. The broader mobile-phone market dropped 6.1 percent.

"It was widely expected that Verizon would get some Android phones," said Dan Ernst, an analyst at Hudson Square Research in New York. The carrier's size will provide a boost to Android products, he said.