Niska Gas Storage Announces Closing of Sale to Carlyle/Riverstone

Business Wire, May 13, 2006

CALGARY, Alberta -- Niska Gas Storage ("Niska"), formerly EnCana Gas Storage, today announced the completion of the first phase of its sale from EnCana Corporation ("EnCana") to the Carlyle/Riverstone Global Power and Energy Fund ("Carlyle/Riverstone"), an energy private equity fund managed by Riverstone Holdings and The Carlyle Group. In conjunction with today's closing, Niska announced that effective immediately it has changed its name from EnCana Gas Storage to Niska Gas Storage ("Niska").

Niska's natural gas storage business is located in key North American natural gas producing and consuming regions and is connected to multiple gas transmission pipelines. Niska and its subsidiaries own and operate approximately 140 billion cubic feet (Bcf) of working gas capacity at three facilities: Suffield - 85 Bcf in Alberta; Countess - 40 Bcf in Alberta; and Salt Plains - 15 Bcf in Oklahoma. The Suffield and Countess gas storage facilities conduct business under the name AECO Hub(TM).

In a second phase of the transaction, Niska expects to complete the purchase of the Wild Goose storage facility - 24 Bcf in northern California - after it receives the requisite regulatory approval by the California Public Utilities Commission. Niska, through its wholly owned subsidiary Starks Gas Storage L.L.C., has received a FERC section 7(c) certificate for its first high deliverability salt cavern storage facility by 2007 in southwest Louisiana which will add a further 19 Bcf of working gas capacity. With the development of Starks and further planned expansions at both the AECO Hub(TM) and Wild Goose, Niska expects to own and operate upwards of 200 Bcf of working gas by 2007 and continue to fortify its position as the largest independent gas storage company.

Riverstone Holdings and The Carlyle Group

Riverstone Holdings and The Carlyle Group are the co-general partners of Carlyle/Riverstone Global Energy and Power Funds. Riverstone, a New York-based energy and power focused private equity firm founded in 2000, has $6.0 billion under management. Riverstone conducts buyout and growth capital investments in the midstream, upstream, power, and oilfield service sectors of the energy industry. The Carlyle Group is a global private equity firm with $39 billion under management. Carlyle invests in buyouts, venture & growth capital, real estate and leveraged finance in North America, Europe and Asia. For more information on Riverstone Holdings or The Carlyle Group see www.riverstonellc.com and www.carlyle.com.

Niska Gas Storage

Niska Gas Storage is the largest independent natural gas storage company in North America. Niska owns and operates 140 Bcf of working gas capacity in three facilities: the AECO Hub(TM) (comprised of the Suffield and Countess facilities) - 125 Bcf in Alberta, and Salt Plains - 15 Bcf in Oklahoma. Niska expects to complete the acquisition of the Wild Goose storage facility - 24 Bcf in northern California - upon approval of the California Public Utilities Commission. Niska is also planning its first high deliverability salt cavern storage facility by 2007 on the Starks salt dome in southwest Louisiana which will add another 19 Bcf of working gas capacity. With further planned expansions of its facilities, Niska expects to own and operate upwards of 200 Bcf of working gas by 2007. Niska is a private company owned by the Carlyle/Riverstone Global Power and Energy Fund. For more information on Niska see www.niskags.com.