Deutsche Telekom AG DTEGn.DE has agreed to a plan by Japanese mobile company Softbank Corp 9984.T to buy T-Mobile US Inc, the fourth-largest U.S. mobile carrier, Kyodo news agency reported, citing industry sources.

Softbank Chairman Masayoshi Son proposed the buyout in a meeting with top executives of T-Mobile and Deutsche Telekom in mid-May and received a positive response, Kydo reported.

A spokesman for Deutsche Telekom, whose shares were up 0.6 percent at 1303 GMT, declined to comment. Softbank was not immediately available for comment.

Earlier this month, a source told Reuters that Sprint Corp, which is owned by Softbank, was meeting with banks to work out funding for its bid for smaller rival T-Mobile US, carrying an estimated $50 billion price tag.

Deutsche Telekom owns a 67-percent stake in T-Mobile US and the company's chief executive two weeks ago said he was open to any consolidation in the U.S. telecoms market.