AmeriGas Partners, L.P.

Blueknight Energy Partners, L.P.

Brookfield Infrastructure Partners L.P.

Buckeye Partners, L.P.

Chesapeake Midstream Partners LP

Compressco Partners, L.P.

Dorchester Minerals, L.P.

Energy Transfer Partners, L.P.

Enterprise Products Partners L.P.

EV Energy Partners, L.P.

Exterran Partners, L.P.

Ferrellgas Partners, L.P.

Genesis Energy, L.P.

Holly Energy Partners, L.P.

Inergy, L.P.

Kinder Morgan Energy Partners, L.P.

Legacy Reserves LP

Linn Energy, LLC

LRR Energy, L.P.

MarkWest Energy Partners, L.P.

Natural Resource Partners L.P.

NuStar Energy L.P.

Penn Virginia Resource Partners, L.P.

Plains All American Pipeline, L.P.

QR Energy, LP

Sunoco Logistics Partners, L.P.

Targa Resources Partners LP

Vanguard Natural Resources, LLC

Williams Partners L.P.

W.P. Carey & Co. LLC