Investment · Property & casualty insurance
Mitsui Sumitomo Insurance to build 15% stake in U.S. specialty insurer W. R. Berkley
- Investor
- Mitsui Sumitomo Insurance (MS&AD) (Tokyo)
- In
- W. R. Berkley, Greenwich, Connecticut
- Value
- Status
- Completed; Mitsui Sumitomo announced on March 5, 2026 that it had reached a 15% stake.
- Date
- 2025-03-28
Mitsui Sumitomo Insurance, part of MS&AD, agreed with W. R. Berkley and its founding family to acquire 15% of the specialty insurer's common stock through open-market or private purchases from third parties. The Berkley family, which owns about 16%, is not selling and no new shares are issued. MSI generally votes with the family above 4.9%, accepted standstill limits, and gets a board nominee once it reaches 12.5%.
Why it matters
The stake gives MS&AD exposure to one of the most profitable U.S. specialty lines insurers without a full takeover. It reflects the push by Japanese non-life groups to grow U.S. earnings as they unwind cross-shareholdings at home.
The deal
Neither company stated a price, because the shares were to be bought at market prices over time. Japan Credit Rating Agency estimated the 15% stake at about $3.8 billion, or roughly ¥565 billion, at the time of the announcement. It said MSI planned to fund the purchase with cash on hand and external financing. Wachtell, Lipton, Rosen & Katz advised the Berkley family on the agreement.
W. R. Berkley agreed to cooperate on MSI's regulatory filings, approvals and accounting treatment. The investment was subject to customary regulatory approvals and was expected to be completed by the end of March 2026.
Building the stake
MSI crossed the 12.5% threshold in early December 2025, which triggered the family's commitment to recommend an MSI director nominee. By January 2026 it held about 55.6 million shares, or roughly 14% of the stock. MS&AD said on March 5, 2026 that MSI had reached 15%. All of the shares were bought from public shareholders in the secondary market, and none came from W. R. Berkley or the family.
Strategy and accounting
MSI's chief executive cited Berkley's first-class track record in the U.S. specialty market. JCR described the investment as a way to make up for the group's relatively weak position in the U.S. and to diversify its business portfolio further. MSI said it would account for W. R. Berkley under the equity method from March 31, 2026, so its share of Berkley's earnings flows into MS&AD's consolidated results.
What to watch
The agreement entitles the family to recommend an MSI designee for the board, subject to review by Berkley's nominating and corporate governance committee and approval by the full board. Search results did not confirm whether an MSI representative has been appointed.
Sources
Kakehashi M&A News home
