Simpson Thacher & Bartlett and Big Four Japanese firms Mori Hamada & Matsumoto and Nishimura & Asahi are advising on KKR's $4 billion takeover bid for Japanese operational software and systems integrator Fuji Soft.

The private equity investor has secured commitments from Singapore-based 3D Investment Partners and another large shareholder, Farallon Capital, to tender their shares. Its newfound backing means that its deal has trumped rival Bain Capital's bid in September, which at that point was 7% higher than KKR's.