By Paritosh Bansal NEW YORK (Reuters) – Sprint Corp has agreed to pay about $40 per share to buy T-Mobile US Inc , a person familiar with the matter told Reuters on Wednesday, signaling progress in a long-contemplated deal to merge the third- and fourth-largest U.S. wireless carriers. At that price, about a 17 percent premium to the carriers Wednesday close, T-Mobile would be worth more than $32 billion. Deutsche Telekom owns 67 percent of T-Mobile and is expected to keep a 15 to 20 percent stake of the combined company as part of the deal, the source said on condition of anonymity because the discussions were private. Still, the broad agreement between Sprint, owned by Japans Softbank Corp , T-Mobile and other parties on issues such as price show that both sides are making progress.