Softbank Corp. is in talks with Deutsche Telekom AG over buying T-Mobile US Inc., as the Japanese firm looks for alternatives to enter the U.S. wireless market if its deal with Sprint Nextel Corp. falls apart, Reuters reported.

Softbank still hopes to complete the deal with Sprint, the third-largest U.S. mobile carrier, and is looking at the possible transaction for T-Mobile, the No. 4 carrier in the United States, only as "Plan B," the report said Friday, citing three separate sources.

The company's talks with Deutsche Telekom, which owns a 74 percent stake in T-Mobile, have intensified in recent weeks after U.S. satellite TV provider Dish Network Corp. lodged a $25.5 billion (¥2.5 trillion) counterbid in April, seeking to trump Softbank's $20.1 billion offer last October for 70 percent of Sprint.

Sprint shareholders are scheduled to meet Wednesday to decide on the two rival offers.