TheTrainline drops IPO and opts for sale to rivalNews / DistributionBy Martin Cowen | January 21, 2015Share Exponent has sold thetrainline.com to rivals KKR, only a fortnight or so after thetrainline.com said it was planning to float on the London Stock Exchange.No other details are currently available. KKR has issued a statement which makes no reference to the proposed IPO.Tnooz reported on the intention to float earlier this month.At the time, reports in the financial press valued the business at £500 million, with Exponent tipped to make around £70 million.The price paid by KKR is not disclosed.