Toshiba Corp shares jumped by nearly a fifth on Tuesday after a US hedge fund said it had added a stake and the Japanese conglomerate avoided an immediate court injunction on a planned $18 billion sale of its chip business.

Toshiba is scrambling to complete the sale of its chip unit to help cover billions in losses at its now-bankrupt Westinghouse nuclear unit.

But the auction has stalled on disagreements among members of the groups bidding for the world’s number two NAND producer as well as a legal battle with Western Digital Corp, its memory chip joint venture partner.

US hedge fund Greenlight Capital, run by David Einhorn, said on Friday the stock may be worth as much as 400 yen once the company resolves its dispute with Western Digital and clears uncertainties around Westinghouse.

Toshiba shares closed up 19 per cent on Tuesday at 275.8 yen, giving the crisis-wracked firm a market value of around $10.4 billion. The Tokyo market was closed on Monday for a national holiday.

The stock is still down around 30 per cent compared with levels since late December when it flagged potential billions in losses.

“I wouldn’t recommend Toshiba to investors. This is a company that cannot even announce its earnings. It could have been delisted,” said Fujio Ando, an adviser at Chibagin Securities.

“Toshiba plans to start selling OLED TVs in the autumn but LG is selling them at half their price. Toshiba could end up losing money on that,” he added.

Western Digital has sought a US court injunction to block the sale, arguing that any sale requires its consent.

The US court judge on Friday postponed a decision on the injunction and proposed requiring Toshiba to give Western Digital two weeks’ notice before closing the sale.