SoftBank Group Corp said on Friday it planned to slash its exposure to wireless carrier SoftBank Corp  to 40.4% from 62.1% now, in a sale worth 1.47 trillion yen ($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 Corp shares closed down 1.6% at 1,431 yen on Friday.

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.

The announcement 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% since March.