TOKYO (Reuters) - Toshiba Corp (>> Toshiba Corp) has received bids ranging from 200 billion yen to as much as 400 billion yen ($1.8-3.6 billion) for a 19.9 percent stake in its flash memory business, a person directly involved in the deal told Reuters on Thursday.

The Japanese conglomerate is seeking to raise around 300 billion yen from the sale, said the person, who was not authorised to speak with media and so declined to be identified.

A sale at that price would help Toshiba offset a multi-billion dollar writedown on its U.S. nuclear power business, which investors worry could wipe out shareholder equity.

Suitors for the Japanese company's chip unit include rivals SK Hynix Inc (>> SK Hynix Inc) and Micron Technology Inc (>> Micron Technology, Inc.), data storage firm Western Digital Corp (>> Western Digital Corp) and financial investors such as Bain Capital, people told Reuters earlier this week.

Toshiba favours bids from investment funds because it could conclude a deal quicker than with industry peers that may have to seek permission from competition regulators before any acquisition, another person close to the matter said earlier.

A Toshiba executive has said the company will consider not just the offer price when selecting a bidder but other conditions as well.

A Toshiba spokeswoman said the company could not comment on specifics of the sale process.

Shares of Toshiba fell 6.7 percent in Tokyo trade on Thursday, a day after Mizuho Securities pointed to the possible market impact of Toshiba being demoted to the second section of the Tokyo stock exchange or even deslisted.

The Nikkei business daily early on Thursday also reported market concerns that Toshiba could delay its third-quarter earnings release, without citing sources.

A Toshiba spokesman said the company would announce earnings on Feb. 14 as planned.

On reporting earnings, Toshiba also plans to reveal the writedown on its U.S. nuclear business that people earlier told Reuters could be as much as 700 billion yen.

($1 = 112.1400 yen)

(Reporting by Taro Fuse and Makiko Yamazaki; Additional reporting by Ayai Tomisawa; Editing by Chris Gallagher and Christopher Cushing)