The company's Midstream Services segment generates revenue through the marketing of its gas production and some third-party natural gas and through gathering fees associated with the transportation of natural gas to market.  The company's gas marketing subsidiary, Southwestern Energy Services Company, was formed to better enable it to capture downstream opportunities which arise through marketing and transportation activity.

Southwestern's gas gathering subsidiary, DeSoto Gathering Company, L.L.C., is engaged in gathering activities related to the development of the company's Fayetteville Shale play.  Gathering revenues and expenses are expected to continue to grow in the future as gathering systems for the company's Fayetteville Shale play are constructed to support the development of this play.