IntercontinentalExchange Group, Inc. (NYSE:ICE) plans to sell as much as 30% of Euronext N.V. before the operator of the Paris and Amsterdam exchanges goes public in 2014, three people with knowledge of the matter said. Euronext's advisers are preparing to start talks as soon as in January 2014 with potential buyers willing to hold their stakes after the initial public offering, said the people, who asked not to be identified because the talks are private. No single investor will be allowed to own more than 10% of Euronext without regulatory approval, a process that could take as long as a year, according to the people.