The merger proposed between Permian Basin producers Diamondback Energy Inc. and Energen Corp. has been approved by each company’s stockholders. Diamondback is acquiring the Birmingham, AL-based operator in an all-stock transaction estimated at $9.2 billion. The merger, set to be completed by Friday (Nov. 29), is giving Midland, TX-based Diamondback a total of 390,000 net acres across the Midland and Delaware sub-basins of the Permian, an 85% increase from Diamondback’s 211,000 net acres at the end of June.