The logo of Toshiba is seen as shareholders arrive at Toshiba's extraordinary shareholders meeting in Chiba, Japan March 30, 2017. REUTERS/Toru Hanai TPX IMAGES OF THE DAY

TOKYO (Reuters) - Apple Inc AAPL.O, Amazon.com Inc AMZN.O and Google have joined bidding for Toshiba's 6502.T NAND flash memory unit, vying with others for the Japanese firm's prized semiconductor operation, the Yomiuri Shimbun daily reported on Saturday.

Toshiba shareholders on Thursday agreed to split off its NAND flash memory business, paving the way for a sale to raise at least $9 billion to cover U.S. nuclear unit charges that threaten the conglomerate’s future.

The Yomiuri newspaper said bidding prices from Apple, Amazon or Google, owned by Alphabet Inc GOOGL.O, were not known.

The Nikkei business daily reported on Friday that U.S. private equity firm Silver Lake Partners SILAK.UL and U.S. chipmaker Broadcom Ltd AVGO.O have offered Toshiba about 2 trillion yen ($18 billion) for the unit.

About 10 potential bidders are interested in buying a stake in the microchip operation, a source with knowledge of the planned sale told Reuters earlier.

Suitors include Western Digital Corp WDC.O, which operates a chip plant with Toshiba in Japan, Micron Technology Inc MU.O, South Korean chipmaker SK Hynix Inc 000660.KS and financial investors.

Toshiba officials were not immediately available for comment.

($1 = 111.3800 yen)