By Ernest Scheyder
HOUSTON (Reuters) - Harold Hamm, chief executive of shale oil producer Continental Resources Inc and Mitt Romney's 2012 energy adviser, endorsed U.S. presidential candidate Donald Trump on Friday, saying he has the "fortitude to make tough decisions."
Hamm, who had previously donated to U.S. Senator Marco Rubio's presidential campaign, called the real estate mogul a "business leader's candidate" who has the will to right what he called a series of mistakes from politicians in Washington, including "burdensome government regulations."
"The next president of the United States must have the courage, determination and intelligence to disrupt politics as usual," Hamm wrote in a public letter.
"Such an honor to get the endorsement of Harold Hamm, one of the great men in the history of the oil and energy business," Trump said in a statement to Reuters.
Known for his outspoken views on U.S. energy policy and other matters, Hamm once referred to OPEC leader Saudi Arabia as a "toothless tiger" in the face of growing U.S. oil output.
OPEC and Saudia Arabia eventually proved Hamm wrong by using its influence to keep prices low for more than 18 months and counting, exerting sharp pain on U.S. oil producers. Hamm's Continental is expected to post a quarterly loss next month.
Hamm's endorsement followed President Barack Obama's meeting with Saudi Arabia's King Salman in Riyadh this week.
By endorsing Trump, Hamm has parted ways with former Massachusetts Governor Mitt Romney, the 2012 Republican candidate for the White House, who has vigorously opposed Trump's candidacy.
(Reporting by Ernest Scheyder and Sneha Johny in Bengaluru; editing by Terry Wade and Tom Brown)