Toshiba and Toshiba Memory filed the lawsuit Wednesday at the Tokyo District Court, seeking an injunction against acts of unfair competition and payment of 120 billion yen ($1.07 billion), among other things.  

Western Digital "has continually interfered with the bid process related to the sale" of the chip unit, Toshiba said in a statement.

The chip unit sale, reportedly worth about 2.0 trillion yen ($18 billion), is seen as crucial for cash-strapped Toshiba to plug massive losses at its US nuclear division, Westinghouse Electric.

But it faces a roadblock as US-based partner Western Digital, which jointly runs a key chip plant in Japan, opposes the sale.

Toshiba executives on Wednesday also had to face angry shareholders criticizing them for having been unable to clinch the deal. 

Last week, Toshiba said it had initiated exclusive talks to sell the firm's prized chip business to a consortium of US, Japanese and South Korean investors.

The company was aiming to announce the sale before Wednesday's investor meeting, but said negotiations were still continuing. "It is taking time to reach a consensus because the consortium comprises multiple parties, and closure was not achieved by Toshiba's primary target date," it said in a statement.

Worst crisis

Toshiba's multibillion-dollar losses at Westinghouse have raised doubts about the future of one of Japan's best-known companies, which is still recovering from a 2015 accounting scandal.

The firm is now is probing whistleblower claims of financial misconduct by senior managers at the nuclear US unit and trying to gauge the impact on its finances.

Toshiba chief executive Satoshi Tsunakawa apologized at the shareholders' meeting for a delayed 2016 earnings report and a recent demotion of the company's shares to the second tier of the Tokyo Stock Exchange. "I apologize for repeatedly causing so much inconvenience and worries," he said.

Toshiba, a 142-year-old Japanese company which has more than 180,000 employees globally, has faced its worst-ever financial crisis since its US nuclear power unit, Westinghouse Electric, filed for bankruptcy protection in March.

sri/rd (dpa, AFP)