U.S. regulators have greenlit ExxonMobil’s acquisition of Pioneer Natural Resources but blocked Pioneer’s former CEO from Exxon’s board.

The deal will see the two Texas-based energy giants combine with Exxon’s $65 billion purchase of Pioneer. As part of the deal, the FTC has barred former Pioneer CEO Scott Sheffield from joining Exxon’s board, citing allegations he attempted to collude with OPEC to spike energy prices by coordinating with domestic shale oil producers to limit output.

Despite not contesting the former CEO’s restriction, Pioneer has reiterated its position, releasing a statement affirming its belief that no wrongdoing was committed.

“As he has for his entire career, Mr. Sheffield is electing to place the interests of investors, employees, and the competitive health of the U.S. energy industry ahead of his own,” read the May 2 public statement.

“At the same time, Mr. Sheffield and Pioneer believe that the FTC’s Complaint reflects a fundamental misunderstanding of the U.S. and global oil markets and misreads the nature and intent of Mr. Sheffield’s actions,” the statement went on to say.

While they did not explicitly answer the question, when asked if they would refer the former CEO’s alleged actions to the U.S. Department of Justice, an FTC spokesperson said, “The FTC has a responsibility to refer potentially criminal behavior and takes that obligation very seriously,” per Reuters.

Some lawmakers, like U.S. Senate Majority Leader Chuck Schumer (D-NY), were unhappy with the FTC’s decision to allow the deal to proceed.

“It is disappointing that FTC is making the same mistake they made 25 years ago when I warned about the Exxon and Mobil merger in 1999,” said Schumer, per Reuters.

In March, The Dallas Express reported that oil and gas producer Denbury Inc. will see 111 jobs cut from its Plano operation beginning this month. The company was acquired last year by Exxon for $4.9 billion.