Bermudian-based White Mountains Insurance Group Ltd has acquired a minority equity stake in Elementum Advisers, an ILS manager with more than $4 billion of assets under management.

Since its launch in December 2009, Elementum, which has an office in Bermuda and is headquartered in Chicago, has grown to become a leading alternative investment management firm.

Elementum manages portfolios across a range of liquidity and risk-return profiles, including catastrophe bonds and collateralised reinsurance investments. It is the third-largest independent manager of insurance-linked securities.

“We are thrilled by White Mountains’ investment in Elementum,” said Tony Rettino and John DeCaro, founding principals at Elementum.

“We believe it will enable us to continue to provide high-quality investment management services to our investors and fortify our business operations and franchise.”

Manning Rountree, chief executive officer of White Mountains, said: “We are delighted to make this investment in Elementum. Tony and John have built a quality business with a strong track record. We look forward to their continued success.”

White Mountains will also invest $50 million across Elementum’s funds. Elementum’s principals continue to own a significant majority of Elementum and will control the operation of the business following this transaction.