Former Pioneer Natural Resources CEO Scott Sheffield told Hart Energy, “For now, I remain one of Exxon’s largest individual shareholders and as such will consider other options.”

Longtime shale boss and North Texas energy magnate Scott Sheffield said he’s no longer interested in joining Exxon Mobil Corp.’s board after the U.S.

Two major oil and gas executives are now allowed to join Chevron and Exxon's board of directors — but only one might be interested.