(Bloomberg) -- Fuji Soft Inc.’s stock surged to above the price offered in Bain Capital’s surprise ¥600 billion ($4.1 billion) buyout bid, signaling expectations for a rare Japan bidding war with KKR & Co.

Bain’s offer threatens to derail an acquisition agreement between the Yokohama-based software company and KKR last month. Bain has now submitted a non-binding proposal to take over Fuji Soft for 5% more than KKR’s original offer of ¥8,800 a share, the companies said in separate statements. That works out to about ¥9,200 to ¥9,300 per share, the Nikkei first reported. Fuji Soft said Tuesday it will consider any legally binding proposal it gets.

Shares in Fuji Soft rose as much as 9.3% to a record intraday high of ¥9,800 during Wednesday morning trade in Tokyo, despite a broad selloff of Asian tech stocks following a tumble in Nvidia Corp.’s stock price.

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If KKR makes a counteroffer, it sets the stage for a bidding war in a country where corporate acquisitions are traditionally negotiated and sealed behind closed doors. But a weaker yen and regulators’ emphasis on shareholder value are now ramping up M&A activity, most recently with Alimentation Couche-Tard Inc.’s proposed buyout of Seven & i Holdings Co.

The move is a sign that the process of realizing shareholder value is continuing, according to Citigroup analyst Mitsunobu Tsuruo.

Emboldened by new guidelines improving governance and protections for shareholders, activist investors have been pushing Japanese companies to unlock value. Fuji Soft has been parrying demands from Singapore-based 3D Investment Partners, its largest shareholder according to Bloomberg-compiled data, to boost shareholder value with steps such as taking the company private.

Bain said it had proposed a take-private offer last year for the company, which contracts software from Fujitsu Ltd., a supplier for some of Japan’s biggest banks such as Mizuho Financial Group and government agencies. Bain “highly valued the target firm’s market advantages, business potential and potential value,” but did not move forward with the deal, as it did not feel Fuji Soft was fully behind a privatization push, the private equity firm said in a statement.

--With assistance from Gareth Allan and Aya Wagatsuma.

(Updates with stock reaction and analyst commentary)