Atlas Pipeline Partners, L.P. Announces New Firm Transportation Agreement with Southwestern Energy on the NOARK Pipeline.

PHILADELPHIA -- Atlas Pipeline Partners L.P. (NYSE:APL) (the "Partnership") announces today a new three-year firm transportation contract with Southwestern Energy Services Company ("Southwestern"), a subsidiary of Southwestern Energy Company (NYSE:SWN), for additional natural gas transportation on the Partnership's FERC-regulated pipeline, Ozark Gas Transmission, LLC ("Ozark Gas Transmission"). The new transportation agreement, which is effective immediately, will add a firm commitment to transport volumes increasing to 175,000 MMBtu per day of natural gas on the Ozark Gas Transmission system in the latter stages of the contract. The agreement will automatically extend for one year periods at the highest commitment amount unless either party elects to terminate the agreement not later than 180 days before the end of the then current term. This agreement brings the aggregate long-term transportation commitments on the Ozark Gas Transmission system to approximately 75% of certificated capacity once the maximum volume per the agreement is reached. The increased transportation volume will be drawn primarily from the Fayetteville Shale development, located in north central Arkansas along the Ozark Gas Transmission pipeline system. Given the existing 322,000 MMBtu capacity of Ozark Gas Transmission, no expansion costs are expected by the Partnership to accommodate the volume.

"We are very pleased to transport the additional production volume from Southwestern in the Fayetteville Shale, and this agreement is a further indication of the success that we are experiencing in this region," stated Edward E. Cohen, Chairman and CEO of the Partnership.

The Partnership acquired 75% of the interest in NOARK Pipeline System, Limited Partnership ("NOARK") from a subsidiary of OGE Energy Corp. (NYSE:OGE) on October 31, 2005. NOARK includes the 565-mile Ozark Gas Transmission pipeline system, extending from southeastern Oklahoma through Arkansas and into southeastern Missouri. NOARK also operates 365 miles of natural gas gathering pipeline in Oklahoma and Arkansas. Another subsidiary of Southwestern Energy Company holds the 25% minority interest in NOARK.

Atlas Pipeline Partners, L.P. is active in the transmission, gathering and processing segments of the midstream natural gas industry. In the Mid-Continent region of Oklahoma, Arkansas, northern Texas and the Texas panhandle, the Partnership owns and operates approximately 2,565 miles of intrastate gas gathering pipeline and a 565-mile interstate natural gas pipeline. The Partnership also operates two gas processing plants and a treating facility in Velma, Elk City and Prentiss, Oklahoma where natural gas liquids and impurities are removed. In Appalachia, it owns and operates approximately 1,500 miles of natural gas gathering pipelines in western Pennsylvania, western New York and eastern Ohio. For more information, visit our website at www.atlaspipelinepartners.com or contact [e-mail].

Statements made in this release may include forward-looking statements, which involve substantial risks and uncertainties. The Partnership's actual results, performance or achievements could differ materially from those expressed or implied in this release as a result of many factors, including competition within the energy industry, climactic conditions, volatility in the price of gas in the Appalachian and Mid-continent area, actual versus projected drilling activity, volumetric production from wells connected to the Partnership's gas-gathering pipeline system, the cost of supplies and services in the energy industry, actions taken by regulatory authorities and the other factors disclosed under "risk factors" in the Partnership's most recent 10-K.