White Mountains Insurance Group Ltd, the financial services holding company domiciled in Bermuda, has revealed that it expects to be exempt from the island’s new corporate income tax through the end of 2029.

The news came as White Mountains announced its fourth quarter and full-year results for 2023.

The company said: “On December 27, 2023, Bermuda enacted a 15 per cent corporate income tax that will generally become effective on January 1, 2025.

“White Mountains expects to meet the requirements to be exempt from the Bermuda corporate income tax and the Pillar Two worldwide minimum tax until January 1, 2030.”

It added: “The Bermuda legislation also provides for an economic transition adjustment that will reduce future years' taxable income. Under US GAAP, this economic transition adjustment was required to be recognised in 2023 and led to the recording of a deferred tax asset as of December 31, 2023.

“Accordingly, White Mountains's results in the fourth quarter and year ended December 31, 2023 included a net deferred tax benefit of $68 million related to the economic transition adjustment, of which $51 million was recorded at Ark and $17 million was recorded at HG Global.

“This tax benefit increased both book value per share and adjusted book value per share by approximately $14, net of non-controlling interest and the impact on the fair value of Ark's contingent consideration.”

White Mountains reported that comprehensive income attributable to common shareholders was $288 million and $511 million in the fourth quarter and year ended December 31, 2023 compared with $40 million and $788 million in the fourth quarter and year ended December 31, 2022.

The company said results in the fourth quarter and year included $66 million and $27 million of unrealised investment gains from White Mountains's investment in MediaAlpha compared with $20 million in gains and $93 million in losses in the fourth quarter and year ended December 31, 2022.

Results in 2022 also included the net gain from the sale of NSM of $876 million.

White Mountains also includes the companies Build America Mutual, Ark, WM Outrigger Re, Kudu Investment Management, David Shield Group and Elementum.

Manning Rountree, the chief executive, said: "We had a strong fourth quarter to cap off a good year. ABVPS (adjusted book value per share) was up 7 per cent in the quarter and 14 per cent for the full year. In the quarter, we had good results from our operating companies and excellent returns in our investment portfolio.

“BAM produced $48 million of gross written premiums and member surplus contributions in the quarter.

“Ark produced good underwriting results in both the quarter and the full year, while growing full-year gross written premiums by 31 per cent.

“Kudu grew the fair value of its continuing portfolio and closed two new deployments in the quarter.

“Our investment portfolio was up 6 per cent in the quarter and 11 per cent for the year.

“The value of our MediaAlpha position grew $66 million in the quarter and $27 million for the year.

“We redeployed $130 million into Outrigger Re for the coming year and closed on our acquisition of Bamboo in early January.

“Undeployed capital stands at roughly $500 million."