TOKYO (REUTERS) - US buyout firm Bain Capital LP plans to bid around 1.5 trillion yen (S$18.78 billion) for a majority stake in Toshiba Corp's chip business, people with knowledge of the matter said.

The bid will be made in partnership with South Korea's SK Hynix but the chip maker will not take a leading role due to anti-trust concerns, the people said, declining to be identified as they were not authorised to speak on the matter.

Bain's bid will allow Toshiba and the management of the memory chip business to own a sizeable holding in the chips unit, the people said, adding that keeping management in place will help the business grow faster.

A Hong Kong-based representative for Bain declined to comment. SK Hynix declined to comment.

The Japanese TVs-to-nuclear conglomerate plans to close a second-round of bidding for the world's second-largest NAND chip manufacturer on Friday but much of the sale is uncertain.

Business partner Western Digital Corp, which jointly runs Toshiba's main semiconductor plant and is one of the suitors for the chip unit, is seeking to block any sale that does not have its consent.

Crisis-wracked Toshiba, which is depending on the sale to cover a US$9 billion (S$12.53 billion) hole in its accounts due to problems at now bankrupt unit Westinghouse, is also open to entertaining new bids after the second round closes, a person with knowledge of the matter has said.