Marathon Oil Corp is seeking bids for its interest in four onshore exploration blocks in East Africa as the oil and gas company focuses on drilling in U.S. shale formations, its advisor on the sale said on Friday.

Marathon, like many other U.S. oil and gas companies, has in recent years directed more capital to shale formations such as the Eagle Ford in south Texas, where production growth is more predictable and returns tend to be higher.

The Houston company will take offers for all or part of the properties located in Ethiopia and Kenya, according to an email from divestiture advisory firm IndigoPool.

Cash bids are due July 23, and a data room will be opened on May 29, the sale notice said.

A spokeswoman for Houston-based Marathon was not immediately available to comment.

Marathon acquired the properties in October 2012, according to the company’s website.

Source: Reuters