Google Inc.'s entry into the wireless market is facing delays, with cellphones based on its operating system unlikely to be released until the end of the year, a media report says.

The company was originally scheduled to have phones based on its open-source Android software for sale during the third quarter, but that has now slipped to the fourth quarter, the Wall Street Journal reported on Monday.

Google has become bogged down with launching Android phones through T-Mobile USA, pushing back launches with Sprint Nextel in the United States and China Mobile, the newspaper said, citing unnamed sources.

Sprint won't be able to launch any Android phones this year, while China Mobile, the world's largest cellphone carrier with 400 million customers, also will be delayed until late this year or early next.

The newspaper said Android has yet to win broad support from third-party software developers, who say it is difficult to program for an operating system that is not yet finished. China Mobile is also said to be having difficulty translating Android from Roman characters into Chinese, as well merging its own branded data services into the operating system.

Earlier this month, Google denied a delay but told the Wall Street Journal that giving its cellphone partners the ability to lobby for new features was taking time.

"This is where the pain happens," said Andy Rubin, director of mobile platforms for the company. "We are very, very close."

Threat to big carriers

Google announced the operating system in November amid much fanfare that it will change the way people use cellphones. The company criticized the industry for having too tight a grip on what sort of software customers could put on their phones and touted the open-source Android as a solution.

The Android phones are seen as a threat to big cellphone carriers, who derive large portions of their revenue from selling customers their own branded services, such as music download stores or GPS applications.

Google wants to make the mobile internet experience more like web surfing on a desktop computer, where it dominates the search and advertising businesses.

Android-based phones are being built for carriers by LG Electronics, Samsung, HTC and Motorola. The new devices should start hitting the market around the same time as new Canadian carriers begin setting up shop following the conclusion of the government's auction of wireless airwaves, currently in its late stages.

Quebecor, Shaw, Eastlink and Globalive are all positioned to win enough spectrum in the auction to set up cellphone networks and could thus potentially bring Android phones to Canada in order to compete with incumbents Rogers, Bell and Telus. None of the incumbents has yet to announce plans to sell Android phones.