UPDATE 1-U.S. oil baron Harold Hamm endorses Trump for president
April 22, 2016 at 18:49 PM EDT
HOUSTON, April 22 (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."