TOKYO — Toshiba, whose U.S. nuclear unit Westinghouse has filed for bankruptcy protection, is reporting an $8.4 billion net loss for the fiscal year that ended in March.

The Japanese electronics giant’s results have failed to win auditors’ approval from the previous quarter, after questions were raised over the acquisition of U.S. nuclear construction company CB&I Stone and Webster.

Tokyo-based Toshiba called the results released today projections, rather than results, since they lack the company’s auditors’ approval, but they were in line with what it had said recently.

The loss was about double the $4.1 billion loss racked up in the previous fiscal year.

Toshiba, whose products include computer chips and household appliances, acquired Westinghouse in 2006. Its president, Satoshi Tsunakawa, has recently said the strategy based on Westinghouse was a mistake, and has promised it won’t take on new nuclear projects.

Westinghouse has its headquarters in Cranberry Township.

Toshiba has been trying to sell its computer-chip business to shore up its finances, but has become embroiled in a dispute with U.S. joint venture partner Western Digital, which is demanding that Toshiba not sell it to anyone else.

Western Digital said that several of its SanDisk subsidiaries have filed a request for arbitration with the ICC International Court of Arbitration over its NAND flash-memory joint ventures with Toshiba.

The request seeks to stop Toshiba’s sale without SanDisk’s consent, arguing that it would be a violation of the joint venture agreement. The arbitration will take place in San Francisco, it said Sunday in a statement.

“Seeking relief through mandatory arbitration was not our first choice in trying to resolve this matter. However, all of our other efforts to achieve a resolution to date have been unsuccessful, and so we believe legal action is now a necessary next step,” said Western Digital Chief Executive Steve Milligan.

Tsunakawa said he doesn’t think Western Digital can block Toshiba.

“With regards to your first question as to whether this may delay bidding procedures, we will make effort to dispel such concerns by explaining to all potential bidders the validity of Toshiba’s position,” he told reporters.

Toshiba also said it expects to return to profit for the fiscal year through March 2018, of $442 million.

Costs in the nuclear industry have ballooned since the March 2011 tsunami in northeastern Japan, when three reactors at the Fukushima Dai-ichi nuclear plant sank into meltdowns, and stricter safeguards are required to operate and build nuclear reactors.