| MarkWest Energy Partners LP | |
| Type: | Subsidiary |
| Foundation: | 1988[1] |
| Location: | Denver, Colorado |
| Key People: | Frank M. Semple (CEO) |
| Industry: | Oil & gas refining and marketing |
| Revenue: | US$ 1.687 billion(2013) [2] |
| Assets: | US$ 9.396 billion (2013) |
| Num Employees: | 1139 |
| Parent: | MPLX LP |
MarkWest Energy Partners, L.P., a subsidiary of MPLX LP, is a natural gas gathering, processing and transportation company master limited partnership of the United States. In 1988, the company was founded in Denver, Colorado and grew to be Colorado's 13th largest company.[3] In 2015 it was acquired by MPLX, itself a subsidiary of Marathon Petroleum.[1] [4]