(Reuters) -Japan's SoftBank Group Corp is looking to raise nearly $4.9 billion in an unregistered overnight block sale of T-Mobile shares, Bloomberg News reported on Monday.

SoftBank is offering to sell 21.5 million shares for $224 to $228 each, Bloomberg said, citing the deal terms. Bank of America Corp is working on the deal.

The sale represents a discount of more than 3% to T-Mobile's closing price of $230.99 on Monday, and the stake offered would represent about 1.9% of T-Mobile's outstanding shares, Reuters calculations showed.

SoftBank and T-Mobile did not immediately respond to Reuters' requests for comment.

In May, the Japanese technology investment group reported a 1.15 trillion yen ($7.94 billion) profit for the year ended March, compared with a loss of 227.6 billion yen a year earlier.

SoftBank's approach of investing in high-growth technology companies is epitomized by the success of its investment in Chinese e-commerce leader Alibaba Group ( BABA ) as well as the bankruptcy of U.S. office-space startup WeWork.

($1 = 144.7500 yen)

(Reporting by Juby Babu in Mexico City; Editing by Anil D'Silva)