Converium, the Swiss re-insurer, is looking to raise $400m (€329m) of fresh capital after being forced to increase its reserves following downgrades by the ratings agencies.

Thomas Jacquet, an analyst at Natexis Bleichroeder, said in a report: "Given the company's now total lack of credibility plus the market's persistent mistrust of the sector, such a capital increase could take place only under dismal conditions. We currently estimate that the move would show a discount of almost 50% on current prices."