Microsoft announced that the premier carrier of its newly unveiled project Windows Phone 7 Series will be AT&T.

The chosen carrier is also the same carrier that is exclusively handling the current popular iPhone by rival Apple.

The announcement came as a surprise as AT&T has been receiving many complaints from users especially with regards to its very spotty 3G connectivity and saturated or slow data speeds. The majority of the complaints came from iPhone users themselves and it was expected that during the launch of the iPad, Apple would announce that they are terminating their relationship.

The reverse happened; Apple even renewed commitments with AT&T. It even defended the carrier. This may what have triggered Microsoft to pick AT&T also, thinking that there is something in there that Apple is seeing that is more valuable than consumer complaints.

However, unlike the iPhone, Windows Phone 7 Series will not be exclusive to AT&T, thus the tag of “premier” carrier. Microsoft has plans to distribute Windows Phone 7 devices through all the four major wireless carriers in the United States.

However, the status and privileges of being the premier carrier is still yet to be defined by Microsoft.