Berkshire Hathaway Inc. is buying Alleghany Corp. for US$11.6 billion in cash, as Warren Buffett returns to the dealmaking he has shied away from in recent years.

Berkshire Hathaway will acquire all outstanding Alleghany shares for US$848.02 per share in cash, according to a statement Monday. The transaction represents a 29 per cent premium to Alleghany’s average stock price over the last 30 days and a 16 per cent premium to Alleghany’s 52-week high closing price, the statement said.

Buffett is diving deeper into the world of insurance with the Alleghany deal, an industry that has been key to the growth of Berkshire into a conglomerate with a market value of more than US$750 billion. With Alleghany, Berkshire gains a large property-casualty insurer that also has reinsurance operations through its Transatlantic Holdings Inc. unit. The business is run by Joseph Brandon, who previously used to be chief executive officer of a Berkshire insurer, General Re.

Read more: BNN Bloomberg