The Tokio Marine & Fire Insurance Company has forged an alliance with China and South Korea's leading non-life insurers.
Under the agreement, People's Insurance Company from China (PICC), Samsung Fire & Marine Insurance and Tokio Marine will exchange staff and knowledge. It will involve sectors including reinsurance, damage assessment, co-operative marketing and co-operative product development.
Tokio Marine has a net premium income of ¥1,349bn (£7.1bn) and a 21% market share in Japan. PICC was formerly the only general insurance company in mainland China and still is the dominant company while Samsung Fire accounts for 30% of South Korea's general insurance book.
Tokio Marine director and general manager of reinsurance Takashi Oka said: "This is the first time that the chief executives of the top three companies in Asia have got together and signed an alliance agreement.
"We have had very good relationships with the companies for a very long time. Each of the organisations will now share their best knowledge within their regions."
Oka added there were no plans for redundancies but the insurers will exchange personnel, particularly trainee staff.
Under the agreement, ACE will acquire 22% of Huatai's outstanding shares for total consideration of about $150m (£103m).