Aug 21 (Reuters) - Permian Resources said on Monday it would buy Earthstone Energy in an all-stock transaction valued at about $4.5 billion, including debt.

The deal would strengthen Permian Resources' position as a leading Delaware Basin independent producer with pro forma production of about 300,000 barrels of oil equivalent per day (boepd).

Delaware Basin, a part of the wider Permian Basin, is a prime target for producers looking to increase their inventory.

The shale patch, which lies between Texas and New Mexico, has the necessary infrastructure and is known for high productivity and large undeveloped reserves. (Reporting by Arunima Kumar in Bengaluru; Editing by Anil D'Silva and Shilpi Majumdar)