* INCJ plans to sell 19 pct stake in chipmaker Renesas
* Sale would gain it around $2.7 bln at current prices
* INCJ seen teaming up with another suitor for Toshiba chip unit (Recasts and adds details of the stock sale)
TOKYO, May 18 (Reuters) - A Japanese state-backed fund plans to sell nearly a fifth of shares in chip maker Renesas Electronics Corp - worth $2.7 billion at current prices - bolstering its coffers amid expectations it is planning to invest in Toshiba's chip unit.
Although the fund, the Innovation Network Corp of Japan (INCJ), has been looking for a partial exit from its investment in Renesas since 2015, the sale comes at a time when sources have said it is preparing to take part in a bid for the world's second-largest producer of NAND memory chips.
Expectations are high that INCJ will join hands to form a consortium with another suitor, although there is little clarity over how much of the bid will be shouldered by the fund.
Toshiba has valued its chip unit at at least 2 trillion yen ($18 billion) and is depending on the sale to help plug to cover billions in dollars in cost overruns at its now bankrupt U.S. nuclear unit Westinghouse.
INCJ's participation is seen as key to success for any bidding consortium as the government is loathe to risk important semiconductor technology leaving the country.
But INCJ officials are cautious about making a large-scale deal, sources familiar with the matter have said, declining to be identified as they were not authorized to speak publicly about the matter. The fund has just 1 trillion yen ($8.8 billion) in its war chest for acquisitions and investment.
A spokesman for INCJ said the sale of Renesas' stock was unrelated to Toshiba.
Other suitors for the chip unit include Taiwan's Foxconn , U.S. chipmaker Broadcom and business partner Western Digital Corp.
INCJ, which currently holds a 69.2 percent stake in the Renesas, plans to sell 19.1 percent of outstanding shares, the chip maker said in a filing. That would be worth 295 billion yen at its Wednesday closing price.
Other shareholders including Hitachi Ltd and Mitsubishi Electric Corp also plan to sell shares, bringing the potential share sale to 24.2 percent.
INCJ rescued a cash-strapped Renesas in 2013 with a 150 billion yen investment. The deal came with the proviso it hold onto the stake for two years. ($1 = 111.2800 yen) (Reporting by Makiko Yamazaki; Editing by Edwina Gibbs)