Diamondback Energy said on Tuesday it would buy certain units of EnCap Investments-backed energy producer Double Eagle for $4.08 billion in cash and stock, expanding its presence in the oil-rich U.S.

The transaction could be valued at more than $5 billion, the Wall Street Journal reported Friday, citing unnamed sources.

EIR analyst Dittmar called the deal a priority for Diamondback “because it represents one of the last current opportunities to get a large, high-quality asset from a private