Sanford "Sandy" Weill, the former head of Citigroup, has stepped down as chairman of Hamilton Insurance Group in Bermuda.

Weill, 82, is retiring effective immediately,and will be replaced as chairman by Chief Executive Brian Duperreault, the insurer said Wednesday in a statement. Weill will still advise the company as a consultant on growth initiatives, Hamilton said.

Weill was one of the "driving forces" in uniting insurance veterans with the analytical skills of Two Sigma Investments, a quantitative hedge fund firm that's a a technology and investment partner of Hamilton. Weill became chairman in January 2014, a month after the venture's formation.

"I will always be grateful to him for believing in Hamilton's potential, and look forward to his wisdom and counsel as a consultant," Duperreault said in the statement.

Hamilton acquired Sportscover Underwriting last year to push into the the Lloyd's of London market and bought units from Fairfax Financial Holdings in 2014 for primary insurance.

"I am proud of what we have accomplished together in a short period of time," Weill said in the statement, without saying why he is leaving.

Weill helped engineer the 1998 merger of insurer Travelers Group and Citicorp, ushering in the era of U.S. financial conglomerates. Neither Duperreault nor a representative for Weill returned messages seeing comment.

Subscribe Now

Access to authoritative analysis and perspective and our data-driven report series.

14-Day Free Trial

No credit card required. Complete access to articles, breaking news and industry data.