AT&T plans to acquire Deutsche Telekom AG's T-Mobile USA for $39 billion in cash and stock, a deal which will alter the telecom landscape in US leaving only three key players in the market.

The deal also gives Deutsche Telekom an 8 percent stake in AT&T. The deal, if approved by regulators, will make AT&T the largest U.S. mobile service provider.

T-Mobile had 33.7 million customers on its grid as of Dec. 31, 2010. The company recorded $4.69 billion in revenues in the fourth quarter of 2010.

Recently, T-Mobile was part of some high-profile tablet launches. In Feb. 2011 T-Mobile launched LG's flagship tablet G-Slate on its network. The tablet runs on Android 3.0 and has a 3D capable 8.9-inch screen.

T-Mobile claims that it's 4G network is the largest in the US, reaching 200 million people across the nation. Its average revenue per user (ARPU) - including both contract and prepaid users - is $46. It has around 26.4 million contract customers and 7.3 million prepay customers.

T-Mobile has around 37,795 employees.

Recently launched phones on T-Mobile network include some key Android phones like Motorola Cliq 2, Google G2, Samsung Galaxy S 4G, LG Optimus T, Motorola Defy and myTouch 4G. Key tablets running on its network are Dell Streak 7 and Samsung Galaxy Tab.

For AT&T it's the T-Mobile infrastructure more than the devices that matters. AT&T needs more capacity to handle increased growth over its network. Randall Stephenson, CEO and Chairman AT&T: This transaction delivers significant customer, shareowner and public benefits that are available at this level only from the combination of these two companies with complementary network technologies, spectrum positions and operations.