Oils rigs in the Permian Basin, Texas. |

Gibson, Dunn & Crutcher and Sullivan & Cromwell are representing Concho Resources in its pending $9.5 billion acquisition of RSP Permian in a deal that will create the largest drilling program in the Permian Basin. RSP turned to Vinson & Elkins.

On March 28, Midland-based Concho and Dallas-based RSP announced a definitive agreement calling for Concho to acquire RSP in an all-stock transaction valued at about $9.5 billion, including RSP net debt. The boards of directors of each company have approved the transaction. Concho shareholders will own about 74.5 percent of the combined company and RSP shareholders will own about 25.5 percent.

The deal, which is expected to close during the third quarter of 2018, creates the largest oil and natural gas producer from unconventional shale in the Permian Basin, and the largest drilling program, with 27 rigs. The acquisition is subject to approval from shareholders of both companies, certain regulatory approvals, and other customary closing conditions.

At Gibson Dunn, Concho's team is led by oil and gas partner Michael Darden and corporate partner Hillary Holmes, both of Houston, with assistance from corporate associates Lindsay Ellis and Harrison Tucker and oil and gas associates Matt Savage, David Cias and Graham Valenta, all in Houston.

Others are tax partner James Chenoweth, corporate partner Tull Florey, finance partner Shalla Prichard and oil and gas partner Justin Stolte, all of Houston; corporate partner Doug Rayburn of Dallas; intellectual property partner Alexander Southwell of New York, benefits partners Michael Collins and environmental partner Michael Murphy, both of Washington, D.C. ; and benefits partner Sean Feller of Century City, California.

The Sullivan & Cromwell team for Concho, all in New York, includes corporate partners Joseph Frumkin and Krishna Veeraraghavan, and associates Daniel Belke and Matthew Aulds.

The V&E team for RSP is led by partners Doug McWilliams, Steve Gill and Lande Spottswood, all of Houston, with assistance from associates Leonard Wood, Jing Tong, Mariam Boxwala, David Bumgardner, Maggie Webber, Andrianna Frinzi, Michael Pascual and Ryan Rivera, all of Houston. Others on the deal include executive compensation/benefits partner David D'Allessandro, senior associate Dario Mendoza and associate Steven Oyler, all of Dallas; tax partner David Peck and associate Megan James, both of Dallas; oil and gas partner John Grand of Dallas; and environmental counsel Larry Pechacek of Houston.