Toshiba Corp. has taken back a majority stake in a joint chip production venture with Western Digital Corp. from its chip unit which the Japanese conglomerate plans to sell off, after the U.S. company took legal action last month to block the sale, sources close to the matter said Wednesday.

Toshiba retook the 50.1 percent stake in the joint venture that it transferred to Toshiba Memory Corp. after it was spun off from the parent company. Western Digital owns the remainder.

Last month the U.S. data storage company took legal action against Toshiba's plan to sell a majority stake in Toshiba Memory, asking the International Court of Arbitration of the Paris-based International Chamber of Commerce to block the sale. The U.S. company also demanded exclusive negotiation rights to purchase Toshiba Memory.

The latest move will allow Toshiba to maintain control over the joint venture, which operates a chip plant in Mie Prefecture, central Japan, even if Western Digital buys Toshiba Memory. It would also keep the planned sale of Toshiba Memory from causing a change of the joint venture ownership structure.

The U.S. company said Thursday that it has no plans to drop its claim following Toshiba's latest move.

"Toshiba has clearly broken its contract," a Western Digital spokesperson said.

The spokesperson added Western Digital is willing to continue holding talks with Toshiba to resolve the matter, saying that the U.S. company "would like to seek a win-win solution for both companies."

But unless Toshiba Memory -- the world's second-largest producer of NAND flash memory chips, which are used in devices such as smartphones -- takes the stake back, the business becomes less valuable and the whole process of finding a buyer could be derailed.

The sale is crucial as the Japanese company is in dire need of raising cash to make up for huge losses from its U.S. nuclear business. The embattled Japanese conglomerate is looking to raise at least 2 trillion yen ($18 billion) by selling a majority stake in its chip unit.

Last month Toshiba projected a record group net loss of 950 billion yen for the year ended March 2017, putting it in the red for the third consecutive year. The Japanese conglomerate also estimated it had a negative net worth of 540 billion yen as of March 31.

Toshiba is hoping to eliminate its negative net worth by next March to avoid getting delisted from the Tokyo stock market.

A total of four bidders, including U.S. investment fund Kohlberg Kravis Roberts and Taiwan's Hon Hai Precision Industry Co., remain as potential buyers. The Japanese turnaround fund is pursuing an alliance with KKR among others.

Other sources said Thursday that Western Digital executives may travel to Japan again next week to hold talks with Toshiba president Satoshi Tsunakawa to work out some compromise.

Tsunakawa and Western Digital CEO Steve Milligan agreed to continue negotiations when they met late last month.

With Western Digital indicating it could make concessions, a plan to get it to join a Japan-U.S. consortium that includes the state-backed turnaround fund Innovation Network Corp. of Japan as an investor had also been discussed then, according to the sources.

Western Digital is continuing to demand it take a controlling interest in Toshiba Corp.'s chip unit, though that could lead to antitrust concerns in countries including China.