T-Mobile is a cellular telecommunications provider owned by Deutsche Telekom in USA. Deutsche Telekom itself based in Bonn, Germany, as part of its T-Mobile division. It was formed from 4 U.S. companies, VoiceStream Wireless, Aerial, Omni Point and Powertel. In May 2001, VoiceStream was acquired by Deutsche Telekom for US$24 billion, and in September 2002 the combined U.S. company's name changed to T-Mobile. T-Mobile USA is currently the fourth-largest wireless carrier in the U.S. market with 33.62 million customers as of the end of the second quarter of 2010 and annual revenue of US$21.53 billion for their 2009 fiscal year.