Toshiba said on Wednesday it has signed a memorandum of understanding (MOU) with Bain Capital Private Equity LP, the lead member of a consortium currently bidding to acquire Toshiba Memory Corporation (TMC), memorializing the parties' intent to negotiate a definitive agreement for the sale of TMC by the end of this month.

Toshiba has been in continuing negotiations with three consortia of potential purchasers of TMC: a consortium that includes the Innovation Network Corporation of Japan, Bain and Development Bank of Japan; a consortium that includes Western Digital; and a consortium that includes Hon Hai.

In the course of these negotiations Bain has come forward with a new proposal, Toshiba said. Toshiba's Board of Directors has determined to continue negotiations with the Bain-led consortium on the basis of this new proposal, and the company will work to expedite the conclusion of a stock purchase agreement by the end of September.

Toshiba added that the memorandum does not exclude talks with other bidders.

Western Digital said in a statement on Wednesday it remains confident it can protect its interests in its memory chip joint venture with Toshiba:

"We are disappointed that Toshiba would take this action despite Western Digital's tireless efforts to reach a resolution that is in the best interests of all stakeholders. Throughout our ongoing dialogue with Toshiba, we have been flexible, constructive and have submitted numerous proposals to specifically address Toshiba's stated concerns. Our goal has been - and remains - to reach a mutually beneficial outcome that satisfies the needs of Toshiba and its stakeholders, and most importantly, ensures the longevity and continued success of the JVs."

"Furthermore, it is surprising that Toshiba would continue to pursue a transaction with a consortium led by Korea-based SK Hynix Inc. and Bain Capital Japan without SanDisk's consent, as the language in the relevant JV agreements is unambiguous, and multiple courts have ruled in favor of protecting SanDisk's contractual rights. We remain confident in our ability to protect our JV interests and consent rights."

Western Digital has filed arbitration requests on May 14, 2017, and July 5, 2017. WD says that both legal actions continue to move forward in the ICC International Court of Arbitration.