American Midstream Partners, LP

AmeriGas Partners, L.P.

Boardwalk Pipeline Partners, LP

Compass Diversified Holdings

Compressco Partners, L.P.

Dorchester Minerals, L.P.

Eagle Rock Energy Partners, L.P.

El Paso Pipeline Partners, L.P.

Enbridge Energy Partners, L.P.

Energy Transfer Partners, L.P.

Enterprise Products Partners L.P.

Exterran Partners, L.P.

Ferrellgas Partners, L.P.

Genesis Energy, L.P.

Inergy, L.P.

Kinder Morgan Energy Partners, L.P.

Legacy Reserves, LP

Linn Energy, LLC

MarkWest Energy Partners, L.P.

Martin Midstream Partners L.P.

Natural Resource Partners L.P.

NGL Energy Partners LP

Plains All American Pipeline, L.P.

Spectra Energy Partners, LP.

Targa Resources Partners LP.

TransMontaigne Partners, L.P.

Vanguard Natural Resources, LLC

Williams Partners L.P.

W.P. Carey & Co. LLC