MARKWEST ENERGY PARTNERS, L.P. 3,000,000 COMMON UNITS REPRESENTING LIMITED PARTNER INTERESTS UNDERWRITING AGREEMENT January 11, 2011Underwriting Agreement • January 14th, 2011 • Markwest Energy Partners L P • Crude petroleum & natural gas • New York
MarkWest Energy Partners, L.P., a Delaware limited partnership (the “Partnership”), proposes to issue and sell to you (the “Underwriter”) an aggregate of 3,000,000 common units (the “Firm Units”) representing limited partner interests in the Partnership (“Common Units”). The Partnership also proposes to issue and sell to the Underwriter not more than an additional 450,000 Common Units (the “Additional Units” and together with the Firm Units, the “Units”) if and to the extent that you shall have determined to exercise the right to purchase such Additional Units granted to you pursuant to Section 2 of this agreement (this “Agreement”).
