By David French and Arathy S Nair

(Reuters) – ConocoPhillips is offering to sell about $500 million in conventional oil and gas properties in the top U.S. oil basin, according to a marketing document seen by Reuters, hoping to unload less valuable acreage after two major shale acquisitions.

On Monday, Houston-based Conoco agreed to buy Royal Dutch Shell’s Permian basin properties for $9.5 billion in cash. In January, Conoco acquired another Permian producer, Concho Resources, for $13.3 billion in stock.

The third-largest U.S. oil producer by market value has hired investment bank RBC Capital Markets to handle the upcoming sale, according to a marketing document dated fall 2021.

The offer covers lower-value oil and gas producing properties in the Central Basin Platform (CBP) and Northern Shelf formations, spread across west Texas and New Mexico.

ConocoPhillips spokesperson Dennis Nuss declined to comment.

RBC Capital Markets did not reply to requests for comment.

U.S. energy companies have stepped up divestments with oil trading above $73 a barrel, a 51% increase this year, and U.S. natural gas prices have almost doubled on rising demand. Chevron Corp and Occidental Petroleum Corp recently offered Permian assets for sale.

ConocoPhillips has signaled its interest in accelerating divestments after the two shale deals. It plans to divest as much as $5 billion in assets by 2023, with a focus on less productive parts of its Permian portfolio, it said this week. It also has said it aims to sell a stake in some of its Alaskan assets.

Its Permian properties were valued at around $500 million, based on proved developed producing (PDP) valuation measures, the marketing document said.

Initial bid proposals are due on Oct. 13. The CBP assets produced about 9,260 barrels of oil and gas per day (boepd), while the Northwest Shelf produced about 3,840 boepd, the document added.

(Reporting by David French in New York and Arathy S Nair in Bengaluru; Editing by David Gregorio)