MarkWest owns and operates the East Texas gathering system and the Carthage gas processing plant in Panola County, Texas. MarkWest currently gathers approximately 420 million cubic feet per day (mcf/d) of natural gas in the East Texas system, an increase of nearly 70% since MarkWest acquired the gathering assets in 2003.

In addition, MarkWest recently executed new long-term agreements that will add significant new gas volumes. To accommodate this growth, MarkWest will invest approximately $28 million to expand the existing gathering system, and will invest approximately $21 million to expand the processing capacity at its Carthage facility from 200mcf/d to 280mcf/d.

Frank Semple, president and CEO of MarkWest, said: We are very pleased to announce another significant expansion of our East Texas system. The rapid growth we have achieved in East Texas over the past few years is a result of the tremendous success of our producer customers and our commitment to provide outstanding service.