Republican presidential candidate Donald Trump is considering nominating Oklahoma oil and gas mogul Harold Hamm as energy secretary if elected to the White House on Nov. 8, according to four sources close to Trump's campaign.

The chief executive of Continental Resources would be the first U.S. energy secretary drawn directly from the oil and gas industry since the Cabinet position was created in 1977, a move that would jolt environmental advocates but bolster Trump's pro-drilling energy platform.

Dan Eberhart, an oil investor and Republican financier, said he had been told by officials in Trump's campaign that Hamm was "the leading contender" for the position.