SemGroup® Corporation (NYSE: SEMG) announced today that James H. Lytal has been elected as the newest member of the SemGroup Board of Directors, effective immediately, to fill a vacancy on the Board. “We are extremely pleased to welcome James to our board,” said Norm Szydlowski, CEO of SemGroup. “Given his wealth of transaction and M&A experience in the midstream, he will provide unique and valuable perspective on the company’s business and growth plans.” Mr. Lytal has extensive relevant experience with a career of more than 30 years in the energy industry. Mr. Lytal began his career in 1980 working as an engineer for subsidiaries of Texas Oil & Gas Corp. In 1987, he was employed by American Pipeline Company where he later became Vice President of Business Development. From 1994 to 2004, Mr. Lytal served as President of Leviathan Gas Pipeline Partners, which later became El Paso Energy Partners and then Gulfterra Energy Partners, where he also sat on the company’s board of directors. In 2004, Gulfterra merged with Enterprise Product Partners where Mr. Lytal served as Executive Vice President until 2009. Most recently, Mr. Lytal has worked as a senior advisor to Global Infrastructure Partners where he was involved in their acquisition of an interest in Chesapeake Midstream Partners, L.P. He is a graduate of the University of Texas and holds a Bachelor of Science degree in petroleum engineering. About SemGroup Based in Tulsa, Oklahoma, SemGroup® Corporation is a publicly traded midstream service company providing the energy industry the means to move products from the wellhead to the wholesale marketplace. SemGroup provides diversified services for end-users and consumers of crude oil, natural gas, natural gas liquids, refined products and asphalt. Services include purchasing, selling, processing, transporting, terminalling and storing energy. SemGroup® is a registered trademark of SemGroup Corporation. Additional Information This communication does not constitute an offer to buy or solicitation of an offer to sell any securities or a solicitation of any vote, consent or approval. No tender offer for the shares of SemGroup has commenced at this time. If a tender offer is commenced, SemGroup may file a solicitation/recommendation statement with the U.S. Securities and Exchange Commission (“SEC”). Any solicitation/recommendation statement filed by SemGroup that is required to be mailed to stockholders will be mailed to stockholders of SemGroup. In addition, SemGroup may file a proxy statement and other documents with the SEC. Any definitive proxy statement will be mailed to stockholders of SemGroup. INVESTORS AND SECURITY HOLDERS OF SEMGROUP ARE URGED TO READ THESE AND OTHER DOCUMENTS FILED WITH THE SEC CAREFULLY IN THEIR ENTIRETY IF AND WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION. Investors and security holders will be able to obtain free copies of these documents (if and when available) and other documents filed with the SEC by SemGroup through the web site maintained by the SEC at http://www.sec.gov. A registration statement relating to the common units of the Master Limited Partnership has been filed with the Securities and Exchange Commission, but has not yet become effective. These securities may not be sold nor may offers to buy be accepted prior to the time the registration statement becomes effective. This announcement does not constitute an offer to sell, or the solicitation of an offer to buy, any securities. Any offers, solicitations of offers to buy or sales of securities will only be made in accordance with the registration requirements of the Securities Act of 1933 or an exemption therefrom.