Toshiba Corp. is fast approaching a cliff on the path to reconstruction after its semiconductor business partner Western Digital Corp. announced Monday it is seeking international arbitration over the struggling tech giant's plan to sell its flash memory business.

To offset a massive liability tied to U.S. nuclear unit Westinghouse Electric Co., Toshiba desperately needs cash by selling the chip business, which is valued at about ¥2 trillion, according to the company.

However, Western Digital's move to take the matter to the International Chamber of Commerce puts a roadblock in the plan and might delay the sale.