Bermuda reinsurer PartnerRe Ltd is selling 13 million preferred shares to raise $325 million.The company, which made a net loss of more than $800 million in the first quarter after dealing with catastrophe losses of more than $1 billion, said there would be a 7.25 percent coupon on the new shares.The company added that it had also granted the underwriters a 30-day over-allotment option for the issuance of up to an additional 1.95 million ($48.75 million) of the Series E preferred shares.PartnerRe president and chief executive officer Costas Miranthis said: “The company was presented with and took advantage of an excellent opportunity to access the capital markets at attractive rates.“This issue enhances our financial flexibility and serves to reduce our overall cost of capital.”The offering is expected to close on June 15. The shares will have a redemption value of $25 each and PartnerRe may redeem them from June 1, 2016 onwards.