TOKYO - Tokio Marine Holdings will form a strategic partnership with Warren Buffett's Berkshire Hathaway by selling a 2.49% stake through treasury share allotment.

The deal grants Berkshire’s reinsurance arm, National Indemnity, access to Tokio Marine’s global insurance portfolio. In return, Tokio Marine gains expanded risk capacity to pursue international growth and joint mergers and acquisitions.

Tokio Marine will use the proceeds-up to 287.4 billion yen ($1.80 billion)-to buy back shares, shielding existing shareholders from dilution.

National Indemnity agreed not to acquire more than 9.9% of Tokio Marine without board approval. Future purchases beyond the initial stake will occur primarily on the open market.