* ICE listing firm in Paris, Amsterdam, Brussels at first
* ICE has lined up anchor investors to take 33 pct stake
* Listing expected next month
(Adds details, background)
PARIS/LONDON, May 27 (Reuters) - IntercontinentalExchange Group (ICE) is pressing ahead with a listing of European exchange Euronext, which two sources familiar with the matter said could achieve a valuation of at least 1.5 billion euros ($2.1 billion).
ICE will sell all or part of the existing shares in Euronext, which will be listed in Paris, Amsterdam and Brussels, it said a statement on Tuesday.
It will also list shares in Lisbon after the initial public offering (IPO), but before the fourth quarter of 2014, it added.
ICE did not give an exact timetable for the flotation, but a source familiar with the matter said earlier this month that the listing was scheduled for June.
ICE said it had lined up a group of so-called anchor investors to take a 33 percent stake in Euronext through a share purchase agreement. Those shares will be bought at a limited discount to the price of the IPO.
The investor group comprises Banco Espirito Santo, BNP Paribas, BNP Paribas Fortis, Societe Generale , Caisse des Depots, ABN Amro, Belgian government investment vehicle SFPI, Bpifrance, Euroclear, ASR Nederland and BPI Vida e Pensoes.
The remainder of the shares will be offered to both institutional and retail investors in the Netherlands, France, Belgium and Portugal, and institutional investors elsewhere through a private placement.
ICE will also offer shares at a discount to the IPO price to all eligible Euronext employees in France, the Netherlands, Belgium, Portugal and Britain.
Euronext operates equity, fixed income and derivatives markets in Paris, Amsterdam, Brussels and Lisbon. The group has also applied for recognised investment exchange status for its Euronext London bourse.
A spin-off of Euronext has been expected since ICE's $11 billion deal last year to take over NYSE Euronext, parent company of the New York Stock Exchange.
($1 = 0.7325 Euros)
(Reporting by Andrew Callus, Clare Hutchison and Freya Berry; Editing by Mark Potter)