Microsoft: Windows Phone 7 will be GSM-only until 2011

Microsoft said this week that it would not have a version of its upcoming Windows Phone 7 operating system compatible with the CDMA standard at launch. Product manager Greg Sullivan told the Wall Street Journal that the company had decided to focus on GSM initially.

While CDMA is quite popular in the US, and is used by three of the top five carriers in the country, GSM is by far the dominant standard worldwide. Microsoft's decision would likely suppress US sales initially given the market share for GSM here is considerably lower than in other countries.

In comments to CNET, Sullivan added the decision to drop Verizon was due to limited resources. "We had to make some trade-offs," he said. "Even Microsoft doesn't have unlimited resources."

Sullivan said that Microsoft expects a CDMA version of its software during the first half of 2011. Although he did not confirm carriers that would participate in the OS' launch, it is expected that AT&T would carry at least three devices according to press reports.

Fourth-place GSM carrier T-Mobile USA is also expected to sell these phones, although it is not clear if it would participate immediately at launch. Microsoft has declined to specify its plans.

Microsoft's statements confirm earlier reporting by Bloomberg which quoted a Verizon spokesperson saying the the carrier would not sell any WP7 devices this year. It does plan to eventually carry phones based on the platform sometime next year.