SoftBank (OTC:SFTB.F) is gearing up to sell a stake in T-Mobile USA (NASDAQ:TMUS) as part of its plan to shore up cash via asset sales. 

In a press release issued Tuesday, the Japanese tech stock confirmed that it decided to explore a potential sale of some of its stake in T-Mobile USA, among other potential financial transactions. SoftBank owns a 25% stake in the wireless carrier. 

A map of the U.S. with  digital dots representing cellular service.

IMAGE SOURCE: GETTY IMAGES.

"SBG is exploring transactions with respect to shares of T-Mobile common stock, including, private placements or public offerings; transactions with T-Mobile or stockholders of T-Mobile, including Deutsche Telekom AG, or third parties; derivative or hedging transactions; margin loans; or other structured transactions," SoftBank wrote in the press release.  

Sources told CNBC that SoftBank wants to unload as much as two-thirds of its holdings, which could fetch it around $20 billion. 

For weeks, rumors have been swirling that SoftBank would sell some of its stake in T-Mobile as it contends with huge losses from its Vision Technology Fund. For its fiscal year ended March 31, the Vision Fund reported a loss of 1.9 trillion yen or close to $18 billion, driven largely by write-offs for investments in Uber and WeWork that went sour.

At the end of March, SoftBank announced it was aiming to sell $41 billion in assets and buy back billions of dollars in shares. It has already announced plans to sell a stake in its Japanese wireless holdings in May and has bought back around $3 billion in shares as of last week.