* Toshiba plans to decide on Wednesday - Nikkan Kogyo
* Toshiba, Western Digital in final stages of talks-Nikkan Kogyo (Adds company comment, background)
Tokyo, Sept 12 (Reuters) - Japan's embattled Toshiba Corp is set to sell its memory chip unit to a consortium led by Western Digital Corp for about 2 trillion yen ($18.3 billion), the Nikkan Kogyo business daily said on Tuesday without citing sources.
Toshiba plans to make a formal decision on Wednesday with the signing of an agreement to come on Sept. 20 after a board meeting on Sept. 20, the Nikkan Kogyo said.
Sources have told Reuters Toshiba's board is due to meet on Wednesday to consider offers from three groups. One person with direct knowledge of the talks said negotiations between Toshiba and Western Digital are ongoing.
The sources declined to be named because they were not authorized to discuss the matter publicly.
A Toshiba spokesman said no decision has been made on the sale of Toshiba Memory, and that the company is not commenting on details of the bidding process.
Toshiba is desperate to sell the unit to cover billions of liabilities at its U.S. nuclear unit Westinghouse.
In addition to the Western Digital-backed consortium which also includes KKR & Co LP and Japanese government investors, Toshiba has said it is also considering a bid led by Bain Capital and South Korea's SK Hynix as well as one by Taiwan's Foxconn.
Sources have told Reuters that Western Digital, which jointly invests in Toshiba's key chip plant, has offered to step back from the consortium's financing as a compromise, but it still wants a future stake in the chip business.
Nikkan Kogyo said the two companies are in the final stages of talks to work out how big a stake Western Digital will eventually have in the chip unit. ($1 = 109.37 yen) (Reporting by Aishwarya Venugopal in Bengaluru, Taiga Uranaka and Ritsuko Ando in Tokyo; Editing by Sriraj Kalluvila and Edwina Gibbs)