Constellation NewEnergy Signs Agreement to Supply New York Stock Exchange with Wind Energy

Constellation Energy (NYSE: CEG) announced today that its subsidiary, Constellation NewEnergy, Inc., has entered into a green electricity purchase agreement with the New York Stock Exchange, a unit of NYSE Euronext (NYX), to supply renewable energy certificates (RECs) to match 100 percent of the approximately 28 million kilowatt-hours of electricity used annually by the NYSE. This agreement between Constellation NewEnergy and the New York Stock Exchange was facilitated by Co-eXprise, Inc, an energy consulting firm.

"The New York Stock Exchange is at the very heart of global financial markets, and this agreement enables us to power a critical part of our operations in a way that is environmentally sustainable,” said Jeffrey Pellet, senior vice president and Global Head of Facilities and Corporate Services, NYSE Euronext. "We’re very pleased to work with Constellation NewEnergy and Co-eXprise to participate in this valuable program.”

The renewable energy certificates supplied by Constellation NewEnergy are Green-e Energy certified from wind energy facilities which are granted certificates for every megawatt hour of emission-free renewable electricity produced. The RECs purchased by the New York Stock Exchange over the two-year term of the agreement will result in more than 57 million pounds of avoided carbon dioxide emissions due to the displacement of grid electricity generation by renewable energy.

"By supporting renewable energy development and greening its operations, the New York Stock Exchange is setting an example that corporations can and should pursue sustainable business practices,” said Michael Kagan, president of Constellation NewEnergy. "Purchasing renewable energy certificates is a way that businesses and institutions can very easily meet internal and external environmental mandates.”

Constellation NewEnergy’s NewMix^SM Wind RECS are sourced from wind facilities located in the United States. Through the purchase of RECs, Constellation NewEnergy and its customers are investing in the operation and development of facilities that generate renewable energy.

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 more than 8,000 listed issues, NYSE Euronext's equities markets – the New York Stock Exchange, NYSE Euronext, NYSE Amex, NYSE Alternext and NYSE Arca – represent nearly 40 percent of the world's equities trading, the most liquidity of any global exchange group. NYSE Euronext also operates NYSE Liffe, the leading European derivatives business 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: http://www.nyx.com.

About Co-eXprise, Inc.

Co-eXprise is the world leader in Collaborative Cost Management solutions that enable customers to reduce, control and manage their most complex and high dollar spend categories. Co-eXprise’s CX4 technology platform allows customers, their internal stakeholders and their suppliers to share critical sourcing and technical information, collaborate throughout a sourcing project, negotiate and implement sourcing results rapidly and effectively. Co-eXprise is delivering Collaborative Cost Management today across dozens of customers in manufacturing, property management, healthcare, retail and government sectors. For more information about Co-eXprise, visit www.co-exprise.com.

About Constellation NewEnergy

Constellation NewEnergy (www.newenergy.com) is a leading competitive supplier of electricity, natural gas and energy-related services to commercial, industrial and institutional customers throughout the United States. A subsidiary of Constellation Energy (NYSE: CEG), Constellation NewEnergy operates in all competitive energy markets throughout the U.S., providing products that enable customers to effectively manage and control energy costs.

About Constellation Energy

Constellation Energy (www.constellation.com) is a leading supplier of energy products and services to wholesale and retail electric and natural gas customers. It owns a diversified fleet of generating units located in the United States and Canada, totaling approximately 7,100 megawatts of generating capacity, and is among the leaders pursuing the development of new nuclear plants in the United States. The company delivers electricity and natural gas through the Baltimore Gas and Electric Company (BGE), its regulated utility in Central Maryland. A FORTUNE 500 company headquartered in Baltimore, Constellation Energy had revenues of $15.6 billion in 2009.