Deutsche Telekom examines a complete merger with its American subsidiary T-Mobile US, in a move that could be the largest M&A deal in history. The German group, which already owns 53% of T-Mobile, plans to set up a new equity swap holding company. The merger would create the world's largest wireless service provider, surpassing China Mobile valued at $235 billion. Discussions are at an early stage and require political support, while the two companies refused to comment.