Hamilton Insurance Group founder Brian Duperreault has written to his staff after leaving to take over as president and CEO of insurance firm AIG.

Mr Duperreault told Hamilton employees that he was not leaving because there were problems at Hamilton — but because there were problems at AIG he was confident he could help fix.

He said: “Hamilton was founded on a bold idea whose time had come. As other industries leapt ahead in their pursuit of value in data and technology, insurance lagged behind.

“It was only a matter of time before someone disrupted the industry. Hamilton’s investors believed that with the right underwriting talent and with Two Sigma’s data science prowess, we could be the ones to do it.

“And we’ve been proven right.”

Mr Duperreault said Hamilton had set up “a nimble, client-focused company widely admired — and in many cases, envied — by the markets in which we do business”.

He added: “In the US, we were the drivers behind the establishment of Attune, a groundbreaking platform for small commercial insurance.

“In Bermuda, we’re redefining what it means to be a Tier 1 company. At Lloyd’s, we came to market with a full suite of product offerings faster than any other syndicate, leveraging technology to strip out much of the inefficiency that plagues Lloyd’s.

“So I know that Hamilton is in great shape. Some of the best minds in the business work here. There’s an energy that’s palpable when you visit our offices.”

Mr Duperreault said: “If you ask me why I’m leaving, it’s not because there are issues at Hamilton.

“I’m leaving because there are issues at AIG. And I think I can help fix them, in no small part by unlocking the potential represented by the Hamilton/Two Sigma/AIG partnership already in place at Attune.”

And Mr Duperreault said the move would be “transformative” for the group he founded nearly four years ago.

He explained: “As part of the expanded partnership with AIG and TSIQ, Hamilton will play a significant role in leading the data-driven evolution in underwriting.

“That’s what we had in mind when we launched this company just over three years ago.”

Mr Duperreault added: “In closing, I want you to know how proud I am of what we’ve done together. I know the best is yet to come.

“I look forward to the opportunities we’re going to have to work together and I thank each and every one of you for your commitment to Hamilton’s present and to its future.”