(Bloomberg News) Mitt Romney, the front-runner for the Republican Party's presidential nomination, appointed Oklahoma oil billionaire Harold Hamm as energy adviser to his campaign.

Hamm, the 66-year-old founder, chairman and chief executive officer of Continental Resources Inc., will be chairman of Romney's Energy Policy Advisory Group, the candidate's campaign office said in a statement today.

Hamm ranked 36th on Forbes magazine's list last year of the 400 wealthiest Americans. His 68 percent stake in Enid, Oklahoma-based Continental, the largest leaseholder in the Bakken oil formation, had a value of $11.2 billion as of yesterday's close.

Romney has attacked President Barack Obama for policies he says increased energy prices. Gasoline prices averaged $3.56 a gallon last month in the U.S., the highest ever for this time of year.

"Mitt's goal of cheap, plentiful energy for the American economy offers the American people a stark alternative to President Obama's goal of driving prices higher," Hamm said in the statement.

With nine months to go before U.S. voters choose a president, Romney has won an estimated 151 of the 1,144 delegates needed to get his party's nomination to oppose incumbent President Barack Obama, more than all three of his opponents combined.

Romney's energy plan calls for establishing fixed timetables for federal decisions on oil, natural-gas and nuclear projects, and a "streamlined approach" to regulation, his campaign said in the statement. He also would urge Congress to amend the Clean Air Act to exclude carbon dioxide from the list of regulated pollutants.

The U.S. should abandon Obama's "course of restricting supply, increasing regulation, and hoping for miraculous new technologies to save the day," Romney said in the statement.

Continental is the largest leaseholder in the Bakken shale, a geologic formation beneath the northern Great Plains that holds more crude than any other deposit in the contiguous U.S.

Hamm began exploring the Bakken almost two decades ago and now controls more than 350 wells. Using intensive drilling and rock-fracturing techniques, Hamm pioneered the oil boom that last year pushed North Dakota's output to a record, exceeding production of Ecuador, an Organization of Petroleum Exporting Countries member.