Shares in struggling upmarket Australian department store David Jones soared on Friday after it received an unsolicited takeover offer from a mystery British bidder. The retail giant, which is battling weak consumer sentiment and an explosion in online shopping, saw its stock jump more than 17 percent, before easing to 12.3 percent higher at Aus$2.54 in early afternoon. In a statement to the market, it said it had received \"an unsolicited letter from a non-incorporated UK entity... indicating its interest in making an offer for the company\". \"The directors do not believe they currently have relevant information to enable them to qualify or value the approach but, should this change, will advise the market accordingly,\" it said. The news helped push other retail shares higher, with David Jones\' key rival Myer up more than four percent at Aus$1.61. In March, David Jones warned its full-year profit could plunge by up to 40 percent as stalling consumer spending curbs demand, while the growth in online shopping was also costing it business.