SC Fundamental Inc. and its affiliates raised their stake in Bermuda-based insurer and reinsurer Sphere Drake Holdings Ltd. to 7.3 percent from 5.7 percent of common shares outstanding.

The investors bought 82,070 shares at $8.19 each between November 14 and November 20, according to a Schedule 13D filed on Friday with the Securities and Exchange Commission.

The SC Fundamental group now holds 1.34 million shares in Sphere Drake, a Hamilton, Bermuda, reinsurance company.

SC Fundamental is a group of hedge funds run by Gary Siegler, who once worked for Carl Icahn, and his partner Peter Collery. The two formerly worked in the corporate finance division of Dillon, Read & Co.