Intercontinental Exchange says its Euronext NV unit would be valued at up to about $2.4 billion following its upcoming initial public offering. The exchange is selling a stake of up to about 60% of Euronext at 19 euros to 25 euros a share. Shares are expected to start trading on June 20 in Paris, Amsterdam and Brussels, with Lisbon to follow by the end of the year. The spinoff will make Euronext independent for the first time since it was purchased by New York Stock Exchange Group in 2007. Intercontinental Exchange took over Euronext in November when it completed its $11 billion acquisition of NYSE Euronext.