Converium Holdings has turned to Financial Dynamics after an unsolicited bid from French firm Scor last month.
The Converium board called in FD's investor relations team after rejecting the bid.
Scor has secured nearly a third of Converium's shares - but it needs 50.1 per cent to force through a merger and create the world's fifth-largest reinsurer.
Converium (formerly Zurich Re) has promised shareholders higher future profits and a share buyback should the company's defence prove successful.
Early indications suggested a ‘white knight' bidder could come in, but Converium has confirmed that no such bidder has yet stepped forward.
Without an alternative bid, FD's job is focused solely on maintaining shareholder satisfaction and support for the Converium board's rejection of Scor's approach.