SemGroup’s Board of Directors has approved the transaction which is subject to customary closing conditions, including bank and regulatory approvals, and is expected to close no later than the fourth quarter of 2011.SemStream Contribution to NGL Energy Partners Conference Call SemGroup will host a conference call for investors today at 2:00 p.m. EDT. The call can be accessed live over the telephone by dialing 800.884.5695, or for international callers, +1 617.786.2960. The pass code for the call is 63379036. A replay will be available shortly after the call and can be accessed by dialing 888.286.8010, or for international callers, +1.617.801.6888. The pass code for the replay is 75857850. The replay will be available until September 14, 2011. Interested parties may also listen to a simultaneous webcast of the conference call by logging onto SemGroup's Investor Relations website at ir.semgroupcorp.com. A replay of the webcast will also be available for a year following the call at ir.semgroupcorp.com on the Calendar of Events-Past Events page. An additional slide deck for SemStream Contribution to NGL Energy Partners will be posted under Investor Relations/Presentations. LCT Capital, LLC is serving as financial advisor and Gibson, Dunn & Crutcher LLP is serving as legal advisor to SemGroup on this transaction. About SemGroup Based in Tulsa, Okla., SemGroup® Corporation (NYSE: SEMG) 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. About SemStream Based in Tulsa, OK, SemStream®, L.P. is a subsidiary of SemGroup Corporation that purchases, transports, stores and distributes natural gas liquids (NGLs) across the United States. SemStream’s products include propane, normal butane, isobutane and natural gasoline.