US private equity group KKR has approached Blackstone to jointly acquire Toshiba, laying the groundwork for a showdown with Bain Capital.

The two groups have held preliminary talks in recent weeks after Toshiba said it would form a special committee to evaluate potential bids from private equity and other investors, according to people with direct knowledge of the discussions.

The takeover is expected to be led by KKR, although talks are still at an early stage and no formal decision has been reached, they added.

KKR and Blackstone’s interest came after Bain secured qualified support for the takeover deal in April from Toshiba’s largest shareholder, Singapore-based investment fund Effissimo.

KKR and Blackstone declined to comment on the talks first reported by Bloomberg.

The deal to take private equity firm Toshiba, valued at $18 billion, will mark a watershed moment for private equity to enter Asia’s largest developed economy.

Still, uncertainty remains about how the private equity group plans to structure the deal given the significant political hurdles facing taking private a 146-year-old brand that operates in sensitive sectors such as nuclear power, defense and semiconductors.

Japanese authorities are unlikely to approve a full-scale takeover of Toshiba by a wholly foreign-owned consortium, bankers and lawyers said, and may require the participation of state-backed investment funds or other Japanese partners.

Toshiba executives have traditionally resisted taking the group private, but the company has been forced to explore options for resolving years of financial turmoil and a conflict with activist shareholders who hold large stakes in Toshiba.

Many of the largest private equity groups have long viewed Japan as a popular target with deep technological, industrial and manufacturing expertise. Many large firms, such as Bain Capital, have already reaped some of the best returns from the region.

Some global buyout funds have focused on large asset sales by company founders and businesses spun off by Japanese conglomerates under shareholder pressure to boost their value.

But even seasoned investors like Bain and KKR can close big deals, still a delicate task that requires years of work and relationship building.

“There is a huge opportunity in Japan for unraveling and supporting founder-led companies,” a private equity executive said recently, warning: “It’s not an easy market. There are more failures than successes. “