Enerplus to Sell Non-Operated Marcellus Interests

Enerplus Corporation is pleased to announce that we have entered into an agreement to sell a portion of our Marcellus natural gas interests in Pennsylvania, Maryland and West Virginia for estimated proceeds of US$575 million, including closing adjustments which take into account production and capital spending from the effective date. The sold interests include approximately 91,000 net acres, primarily non-operated, in southwest and central Pennsylvania, Garrett County in Maryland and northern West Virginia, with an independent contingent resource assessment of 1.6 Tcfe of natural gas as of December 31, 2010. Proved plus probable reserves associated with these leases at December 31, 2010 were 24.5 Bcfe and current production is approximately 5.4 MMcfe/day. We anticipate closing the transaction by the end of the second quarter, subject to customary closing conditions.

“The sale of a portion of our non-operated leases captures a significant gain for Enerplus and improves our financial flexibility and ability to pursue our capital investment strategies. In addition, we are retaining a concentrated, meaningful position in this top tier shale play,” says Gordon Kerr, President & Chief Executive Officer of Enerplus. As a result of the sale, Enerplus has increased the concentration of operated acreage and will have a greater ability to control the pace and level of capital spending going forward. Enerplus will retain its current non-operated interest in the prolific northeastern Pennsylvania region which has outperformed our production expectations over the past 18 months.

Enerplus first entered into the Marcellus in 2009 via a joint venture arrangement with Chief Oil & Gas Ltd. (“Chief”), purchasing a 21.5% working interest in 540,000 gross acres. Subsequent to that transaction, we purchased additional leases and increased our ownership to over 200,000 net acres. Upon conclusion of this transaction, Enerplus will retain all of our non-operated acreage in Bradford, Susquehanna, Lycoming, Columbia, Tioga, Wyoming and Sullivan counties in northern Pennsylvania as well as our operated acreage in Clinton County, Pennsylvania, Garrett County, Maryland and Preston County, West Virginia. We will retain ownership in approximately 110,000 net acres of land with an independent best estimate of 2.3 Tcfe of natural gas contingent resource and 92 Bcfe of proved plus probable natural gas reserves, each as of December 31, 2010. Of this total, approximately 60% (or 66,000 net acres) will be operated by Enerplus. Proceeds from the transaction will more than eliminate our current bank debt. The assets being sold had a forecast exit production of approximately 20 MMcfe/day. We will be reviewing our capital spending and production guidance for 2011 as a result of the transaction and will provide an update at a later time.