NEW YORK ( TheStreet) -- NYSE Euronext ( NYX), the operator of the New York Stock Exchange, is in talks to sell itself to rival IntercontinentalExchange ( ICE), according to reports. People close to the discussions told The Wall Street Journal an announcement could come as early as Thursday. Under a deal, ICE would value NYSE at $33 a share, a 37% premium to its closing price on Wednesday, according to a report from CNBC. NYSE closed Wednesday at $24.05 and soared more than 20% in after-hours trading. Spokespeople for both companies wouldn't comment. -- Written by Joseph Woelfel >To contact the writer of this article, click here: Joseph Woelfel >To submit a news tip, send an email to: firstname.lastname@example.org.