White Mountains Insurance Group has closed the sale of a controlling interest in Bamboo, the California-based insurtech, to affiliates of CVC Capital Partners, while keeping a minority stake in the fast-growing homeowners’ insurance platform.

The Bermudian-based holding company said yesterday it continues to retain about 15 per cent of Bamboo on a fully-diluted basis.

The deal, first announced in October, valued Bamboo at about $1.75 billion. White Mountains had acquired its majority position in 2023 through a roughly $285 million investment that gave it close to 70 per cent of the company at the time.

Bamboo operates as a tech-enabled, capital-light managing general agent focused on homeowners’ insurance, with a strong footprint in California and a mix of underwriting, distribution and captive reinsurance capabilities. The company also runs a retail agency offering complementary products such as flood and earthquake cover.

When the transaction was announced, White Mountains said it expected to receive approximately $840 million in net proceeds and to record a gain of about $310 per share in book value. The retained 15 per cent stake was valued at roughly $250 million based on the deal terms.

In October, Manning Rountree, chief executive of White Mountains, called the deal “a testament to the value and innovation it [Bamboo] is bringing to the homeowners' insurance market.

“This transaction is a win-win for both White Mountains shareholders and Bamboo management and employees,” he added.

The sale fits White Mountains’ longstanding strategy of building speciality insurance platforms and monetising them once they reach scale. The group previously held businesses such as Esurance, which it sold in 2011.

CVC is expected to support Bamboo’s next phase of expansion, the company has said.