NEW YORK ( TheStreet) -- The ex-dividend date for MarkWest Energy Partners (NYSE: MWE) is tomorrow, February 4, 2014. Owners of shares as of market close today will be eligible for a dividend of 86 cents per share. At a price of $70.54 as of 9:50 a.m. ET, the dividend yield is 4.9%. The average volume for MarkWest Energy has been 868,300 shares per day over the past 30 days. MarkWest Energy has a market cap of $10.48 billion and is part of the basic materials sector and energy industry. Shares are up 6.1% year to date as of the close of trading on Friday. Markwest Energy Partners, L.P., together with its subsidiaries, engages in the gathering, processing, and transportation of natural gas the United States. The company has a P/E ratio of 142.2, above the S&P 500 P/E ratio of 17.7.