WASHINGTON (Reuters) -The U.S. Federal Trade Commission on Thursday reversed bans on the CEOs of takeover targets joining the boards of Chevron and Exxon Mobil that the Biden administration made a condition of clearing the oil giants' deals to buy two oil producers.

The FTC released Exxon, which acquired Pioneer Natural Resources last year, from an order barring former Pioneer CEO Scott Sheffield from its board. Chevron, which agreed to buy Hess in 2023 for $53 billion, was released from a similar order keeping that company's CEO, John Hess, off its board.

The decisions are the latest move by FTC Chairman Andrew Ferguson to reverse actions by his Democratic predecessor, Lina Khan.

Khan and her Democratic colleagues had raised concerned Hess and Sheffield would coordinate with members of the Organization of the Petroleum Exporting Countries. Ferguson and Republican Commissioner Melissa Holyoak dissented at the time, saying the orders exceeded the FTC's authority.

"We are very pleased with the FTC's unanimous decision," a Chevron spokesperson told Reuters.

"I appreciate the current commissioners for their willingness to review this case, and I'm obviously pleased that objectivity and fairness has carried the day in their decision to vacate the prior order," Sheffield said.

Exxon and Hess did not immediately respond to Reuters requests for comments.

While the FTC's three Republican commissioners voted unanimously to reverse the decisions, Commissioner Mark Meador said in a statement that OPEC and OPEC+ "operate as a de facto cartel," making oil markets highly concentrated. The FTC "should not hesitate to bring enforcement actions against actual collusion as well as invitations to collude," he said.

Chevron struck a deal to acquire smaller U.S. oil producer Hess in October 2023, with an eye on the latter's 30% stake in the prolific Stabroek Block in Guyana that is operated by ExxonMobil with a 45% interest.

ExxonMobil and Hess are locked in an arbitration case, with a ruling related to a major oilfield project in Guyana set to determine whether Chevron can move forward with its planned acquisition of Hess.