Key Takeaways ExxonMobil said it completed its deal to buy Pioneer Natural Resources valued at nearly $60 billion after U.S. regulators set conditions.Including debt, ExxonMobil is committing about $64.

Exxon Mobil’s $60 billion deal to buy Pioneer Natural Resources has received clearance from the Federal Trade Commission, but the former CEO of Pioneer was barred from joining the new company’s board of directors.

The Federal Trade Commission is barring Pioneer Natural Resources’ former CEO Scott Sheffield from being a part of its $64.5 billion deal with Houston-based oil giant Exxon Mobil. The commission claims Sheffield colluded with state oil ministers and high-ranking individuals from the Organization of the Petroleum Exporting Countries to increase Pioneer’s profits.

Exxon Mobil has completed its $60 billion acquisition of rival Pioneer Natural Resources after reaching an agreement with antitrust regulators, closing out the largest oil-and-gas deal in decades.

Spring-based Exxon Mobil Corp. (NYSE: XOM) officially closed its acquisition of Pioneer Natural Resources Co. on May 3. The all-stock acquisition was valued at $59.5 billion, or $253 per share, based on Exxon's closing price on Oct.

Sheffield, the FTC alleges, "campaigned to organize anticompetitive coordinated output reductions between and among U.S. crude oil producers"