Exxon Mobil boss Rex Tillerson 'to be US Secretary of State'

Exxon Mobil chief executive Rex Tillerson is to be selected by Donald Trump as his Secretary of State, NBC News reports.

He emerged as the President-elect's leading candidate to be America's top diplomat on Friday and met the billionaire on Saturday, a transition official said.

His expected appointment comes after former New York mayor Rudy Giuliani formally withdrew from consideration for the job.

Ex-Republican presidential nominee Mitt Romney, who lost to Barack Obama in the 2012 election, is also said to have been among those in the running.

Mr Tillerson, 64, has been chairman and chief executive officer of Exxon Mobil since 2006 and he is set to retire from the company next year.

Mr Trump's spokesman Jason Millerin said there would be no official announcements on the Secretary of State job until next week at the earliest.

Should Mr Tillerson be nominated, his business ties will come under scrutiny.

Exxon Mobil operates in more than 50 countries and explores for oil and natural gas on six continents.

In 2011, his company signed a deal with Rosneft, Russia's largest state-owned oil company, for joint oil exploration and production.

Since then, the companies have formed 10 joint ventures for projects in Russia.

In 2013, President Vladimir Putin awarded Mr Tillerson his country's Order of Friendship.

The oil chief has been a vocal critic of US sanctions against Moscow after Russia's 2014 incursion into Crimea.

Following the incursion, Exxon Mobil was forced to scrap some projects and it suffered at least $1bn (£800m) in losses.

Mr Trump has spoken of wanting closer relations with Moscow, which has sparked concerns in Congress he could lift or loosen some Russian sanctions.

Climate change could be another divisive issue if Mr Tillerson is nominated.

The company is under investigation by the New York Attorney General's office for allegedly misleading investors, regulators and the public on what it knew about global warming.