Deutsche Telekom mobile phone division T-Mobile USA is to buy Suncom Wireless Holdings for about $1.6 billion.
Deutsche Telekom said it would also take on Suncom debt of almost $800 million from the transaction of about $1 billion.
Suncom shareholders will receive $27 per share, a 22.7 per cent premium to Friday's closing price, the companies said.
The deal is subject to regulatory and Suncom shareholder approval and is expected to close in the first half of 2008, Telekom added.
Shares in Deutsche Telekom were 0.6 per cent lower at 13.59 earlier this morning, slightly outperforming a 0.7 per cent drop on the German blue-chip DAX index.
Suncom, founded in 1999, operates in the southeastern United States and the Caribbean and had more than 1.1 million customers by the end of June. It posted second-quarter revenue of $242.5 million.