* Apax given due diligence access until Dec. 12 (Adds details of the deal, analyst comment and background on the company): (Reuters) - New Zealand’s online marketplace pioneer Trade Me Group (TME.NZ) received a NZ$2.54 billion ($1.73 billion) takeover bid from a British private equity firm on Wednesday, sending its shares soaring. London-based private equity group Apax Partners was offering NZ$6.4 for each share of Trade Me, the company said in a statement on the New Zealand stock exchange. The offer represents a 25.5 percent premium to Trade Me’s last close of NZ$5.1.