Bear Wagner Specialists LLC Selected by MarkWest Energy Partners, L.P. to Trade Common Units on NYSE.

NEW YORK -- Bear Wagner Specialists LLC today announced that it was chosen by MarkWest Energy Partners, L.P. (NYSE: MWE) to trade its common units on the New York Stock Exchange. MarkWest Energy Partners, which had previously traded on the American Stock Exchange, began trading on the NYSE on May 2.

"We are pleased to welcome MarkWest Energy Partners into the Bear Wagner family of high-quality companies traded by our team of experienced specialists," said Peter Murphy, chief executive officer of Bear Wagner Specialists. "At Bear Wagner, we have maintained a leadership position in exchange transfers by providing our clients with high levels of customer service and superior trading expertise."

"We chose Bear Wagner Specialists as our partners on the floor of the NYSE because we believe they will deliver a superior market for our common units," said Frank M. Semple, president and chief executive officer of MarkWest Energy Partners. "Bear Wagner's substantial trading experience made our transfer from the American Stock Exchange to the NYSE smooth and successful."

About MarkWest Energy Partners, L.P.

MarkWest Energy Partners, L.P. is a publicly traded master limited partnership with a solid core of midstream assets and a growing core of gas transmission assets. It is the largest processor of natural gas in the Northeast and is the largest gatherer of natural gas in the prolific Carthage field in east Texas. It also has a growing number of other gas gathering and intrastate gas transmission assets in the Southwest, primarily in Texas and Oklahoma.

About Bear Wagner Specialists LLC

Bear Wagner Specialists LLC, a leading NYSE specialist firm, is a strategic partner and trusted advisor to many of the world's most esteemed companies. Representing more than 350 publicly traded equities with an aggregate market cap greater than $2.8 trillion, Bear Wagner is widely recognized as the most progressive and technologically advanced firm on the Exchange. Bear Wagner Specialists has vast experience assisting companies as they navigate the NYSE listing process and establish their "best practices" investor relations programs. Bear Wagner Specialists LLC is a subsidiary of The Bear Stearns Companies, Inc. (NYSE:BSC). For additional information, visit the firm's website at www.bearwagner.com. Bear Wagner Specialists LLC is a member of SIPC.