STS Group lists on NYSE Alternext in Brussels

11th company to be listed on NYSE Alternext in Brussels

Brussels - 22 February 2011 – NYSE (NYX) today announced the cross-listing of STS Group, software publisher and European leader in the digital trust area, on NYSE Alternext in Brussels under the symbol ALSTS.

Founded in 2000, STS Group specializes in Digital Trust. Digital trust includes the authentication, exchange and "probative value" storage of any digital object. The group's product, STS Suite, allows private and business users to securely exchange, track, conserve and consult all of their digital material via the Internet or through the company's own network, guaranteeing the legal value of these digital documents.

STS Group was admitted to NYSE Euronext in Brussels through the listing of 6,217,884 existing shares representing the outstanding capital of the company. These shares have been listed on NYSE Alternext in Paris since 30 September 2010. Market capitalization of STS Group at yesterday’s closing was €94.7 million.

“We extend a warm welcome to STS Group on NYSE Alternext in Brussels. We are very pleased to accompany the company in this new phase in its development, fuelling growth and extending its reach to the Belgian financial community”, said Vincent Van Dessel, CEO NYSE Euronext Brussels.

“We are delighted to welcome STS Group to NYSE Alternext in Brussels,” said Ronald Kent, Group Executive Vice President of International Listing at NYSE Euronext.’ NYSE Alternext is a market well suited to innovative business seeking outstanding visibility as they pursue their growth strategies.”

Bernard Calvignac, Chairman and CEO of STS Group, added: “This dual listing is an important stage in our development as it will help to further enhance the international reach of our company and our software.”

Press Contacts: NYSE Euronext: Anne De Gang: +32 2 509 13 92

STS Group Benelux: Nathalie Brigode: +32 2 482 35 40

About NYSE Euronext NYSE Euronext (NYX) is a leading global operator of financial markets and provider of innovative trading technologies. The company's exchanges in Europe and the United States trade equities, futures, options, fixed-income and exchange- traded products. With approximately 8,000 listed issues (excluding European Structured Products), NYSE Euronext's equities markets – the New York , NYSE Euronext, NYSE Amex, NYSE Alternext and NYSE Arca – represent one-third of the world's equities trading, the most liquidity of any global exchange group. NYSE Euronext also operates NYSE Liffe, one of the leading European derivatives businesses and the world's second-largest derivatives business by value of trading. The company offers comprehensive commercial technology, connectivity and market data products and services through NYSE Technologies. NYSE Euronext is in the S&P 500 index, and is the only exchange operator in the S&P 100 index and Fortune 500. For more information, please visit: www.nyx.com.

About SNS Group: STS Group is a software publisher and European leader in the digital trust area. Digital trust includes the authentication, exchange and "probative value" storage of any digital object. STS Group markets its software offer via a worldwide network of digital trust platforms. After ten years, STS Group recorded in 2009 €23.5m of revenue and profit of €6.3m, with €60m in equity. The Company reiterates it does not have the status of Issuer raising funds from the public and so the share offering can only be made to qualified investors acting on their own behalf under Article L. 411-2 of the French Monetary and Financial Code. STS Group is listed on NYSE ALTERNEXT since September 2010 (codes ALSTS – FR0010173518). More information on: http://www.group-sts.com/befr/index.php