An investigation on behalf of current investors in Atlas Energy Resources, LLC (NYSE: ATN), who purchased their ATN shares before Monday, April 27, 2009, over potential breach of fiduciary duty by the board of Atlas Energy Resources, LLC (NYSE: ATN) over unfair takeover was announced.

According to the investigation by a law firm the investigation focuses on potential shareholder claims concerning breaches of fiduciary duty by the board of directors of Atlas Energy Resources, LLC (NYSE: ATN) arising out of their attempt to sell Atlas Energy to Atlas America, Inc. under the given conditions as they appear to be unfair to the shareholders of Atlas Energy Resources, LLC (NYSE: ATN).

On Monday Natural gas companies Atlas America (NASDAQ: ATLS) and Atlas Energy Resources (NYSE: ATN) announced the proposed takeover of Atlas Energy Resources by Atlas America. Under the present conditions Atlas Energy Resources LLC would agree to become a wholly owned subsidiary of Atlas America Inc., which will change its name to Atlas Energy Inc. if stockholders of both companies approve the deal. In the deal, each common unit of Atlas Energy Resources, LLC (NYSE: ATN) not owned by Atlas America will be converted into 1.16 shares of Atlas America common stock. Based on a closing price of Atlas America, Inc shares (ATN) on Friday, April 24, 2009 of $12.41 per share, Atlas Energy Resources, LLC (NYSE: ATN) shareholders would receive a cash equivalent of $ 14.39 per ATN share. Atlas Energy Resources, LLC (NYSE: ATN) shares traded on Friday at $14.35 and inclined to $14.51 on Monday as a result of the announcement. Considering this calculation Atlas America offers the shareholders of Atlas Energy Resources (NYSE: ATN) no premium in the proposed takeover. The investigation adds that the offered price seems to be also unfair to shareholder of Atlas Energy Resources, LLC as shares of Atlas Energy Resources, LLC (NYSE: ATN) traded as high as $16.50 per share on February 13, 2009, reached $22.09 per share as recently as November 2008, and traded over $44 per share in 2008. Atlas America (NASDAQ: ATLS) owns already 48 percent of the common units and all of the management incentive interests of Atlas Energy (NYSE: ATN). In addition to its stake in Atlas Energy, Atlas America owns 1.1 million common units in Atlas Pipeline Partners LP (NYSE:APL), a natural-gas transmission, gathering and processing partnership. It also owns 64 percent of Atlas Pipeline Holdings LP (NYSE: AHD), which owns the general partner interest, all the incentive distribution rights and 5.8 million common units of Atlas Pipeline Partners.

Several present directors and officers of Atlas Energy Resources served or serve in a similar positions at Atlas America, Inc. Edward E. Cohen has been the Chairman of the Board and Chief Executive Officer of Atlas Energy Resources, LLC since the formation in 2006, but he has been also the Chief Executive Officer and President of Atlas America since its formation in September 2000. The Vice Chairman of the Board of Atlas Energy Resources, Jonathan Cohen, Edward Cohens son, has been also the Vice Chairman of Atlas America. Daniel C. Herz has been a Senior Vice President of Corporate Development of Atlas Energy Resources since August 2007, but he has also been the Senior Vice President of Corporate Development of Atlas America. Lisa Washington has been Chief Legal Officer and Secretary since Atlas Energy Resources, LLC formation in 2006, but she has been also the Vice President, Chief Legal Officer and Secretary of Atlas America and Atlas Pipeline Partners GP since November 2005. Matthew A. Jones has been the Chief Financial Officer of Atlas Energy Resources, LLC since the formation, but he has also been the Chief Financial Officer of Atlas America since March 2005. Sean McGrath was appointed to the position of Chief Accounting Officer of Atlas Energy Resources, LLC effective December 30, 2008 and also effective December 30, 2008, Mr. McGrath will assume the position of Chief Accounting Officer of Atlas America, Inc. Atlas Energy Resources, LLC is an independent developer and producer of natural gas and oil, with operations in the Appalachian Basin, where Atlas Energy focuses on the development of the Marcellus Shale, northern Michigans Antrim Shale, and Indianas New Albany Shale. Atlas Energy Resources, LLC is located in Moon Township, PA and had $787.40million in total revenue in 2008 and $577.90million in 2007 with an net income of $142.78million in 2008 and $117.50 in 2007.