Diamondback Energy Inc. is expanding its leasehold in the Permian Basin with two separate cash and stock deals valued at a combined roughly $3 billion that are seen boosting cash flow and shareholder returns.

The Midland, TX-based independent agreed to acquire QEP Resources in an all-stock transaction valued at around $2.2 billion, including QEP’s net debt of $1.6 billion. Under the deal, already approved by each company’s board, QEP shareholders would receive 0.05 shares of Diamondback common stock for each share of QEP common stock, representing an implied value to each QEP stockholder of $2.29 per share based on the closing price of Diamondback common stock on Dec. 18.

Diamondback would gain about 49,000 net acres in the Midland Basin, most of which is held by production...