SoftBank Group is planning to slash its stake in wireless carrier SoftBank to 40.4 percent from 62.1 percent now, in a sale worth 1.47 trillion yen or $13.8 billion at Friday’s closing price.

The offer price for the 1.03 billion shares, including over-allotment, will be set between Sept. 14-16.

SoftBank Group Chief Executive Masayoshi Son has been selling down the group’s core assets to stabilise its balance sheet and fund a record share buyback amid the coronavirus outbreak.

Earlier, SoftBank sold its US telecom business Sprint, the fourth largest mobile operator in the United States, to T-Mobile US, a subsidiary of Germany-based Deutsche Telecom, in a merger deal.

The announcement today marks the expansion of stake sales beyond the 4.5 trillion yen asset sale plan announced in March, with SoftBank saying it needs to stockpile cash to weather the pandemic.

Japan’s third-biggest wireless carrier will remain a group subsidiary, SoftBank said, fitting a pattern of the conglomerate exerting influence over listed investments without holding majority stakes.

SoftBank said it will hold the remaining shares “for the medium to long term”. Son built up the wireless carrier but in recent years has refocused on tech investing.

Separately on Friday, SoftBank Corp said it will spend up to 100 billion yen buying back its shares, which have languished even as its parent’s share price has leapt around 140 percent since March.