Italian investment firm Exor has changed conditions on its $US6.8 billion ($9.16 billion) hostile takeover bid for PartnerRe, improving the cash offer to shareholders.

In January PartnerRe and fellow Bermuda reinsurer Axis agreed to merge, and PartnerRe has consistently rejected Exor’s later offer.

There are also rumours that another Bermuda reinsurer, Arch Capital, is considering a bid.

There were further twists and turns to the takeover with reports that PartnerRe’s former CEO Patrick Thiele had offered to help PartnerRe Chairman Jean-Paul Montupet with the Axis merger in January, and then sought to work with Exor if it took over the company.

PartnerRe shareholders will vote on the Axis proposal on July 24.

Exor holds about 10% of PartnerRe, making it the largest single shareholder.