U.S. energy major Marathon Oil said Monday it signed a deal to sell off some of its non-core assets in the southern United States for $235 million.

To an undisclosed buyer, Marathon said it sold non-core assets in western Texas and New Mexico. The properties included in the deal produced around 4,000 barrels of oil equivalent per day during the first half of the year.

"Since August 2015, Marathon Oil has announced or closed non-core asset sales in excess of $1.5 billion," the company said in a statement.

The largest of the latest sales includes the release of properties in Wyoming that were producing on average 16,500 barrels of oil equivalent per day during the first quarter of the year. For a combined divestment of $870 million, the sale to an undisclosed third party includes about 600 miles of export pipeline from the Big Horn and Wind River basins in the state.

A separate $80 million sale includes gas basins in Colorado, undeveloped property in the Western part of Texas and a 10 percent stake in Shenandoah discovery in the Gulf of Mexico.

Marathon last year sold some of its acreage in the Gulf of Mexico for $205 million, but said it was keeping its interests in the emerging Shenandoah basin. In June, it spent $888 million to acquire PayRock Energy Holdings, which held about 61,000 acres of land in the Anadarko shale reserve area in Oklahoma.

The company said it expects North American production to be about 4 percent less than that during the second quarter, reflecting lower capital investments. Third quarter results are due Nov. 2.