Occidental Petroleum on Monday agreed to buy closely-held U.S. shale oil producer CrownRock in a cash-and-stock deal valued at $12 billion including debt, expanding its presence in the largest U.S. shale oilfield. The deal comes amid a new wave of shale consolidation underpinned by Exxon Mobil’s $60-billion proposed deal for Pioneer Natural Resources and Chevron’s $53-billion agreement for Hess in October.
