According to Bloomberg:

Exxon Mobil Corp. Chief Executive Officer Rex Tillerson is emerging as Donald Trump’s choice as secretary of state, a move that would hand top diplomatic powers to a man whose ties to Russian President Vladimir Putin go back almost two decades.

A source close to Trump said the president-elect had not formally offered Tillerson the job yet but is likely to do so. An announcement is expected in the next few days, according to the person, who asked not to be identified discussing internal deliberations. NBC earlier reported that Tillerson was Trump’s pick. Tillerson met with Trump for more than two hours on Saturday.

From Time Magazine:

If chosen, Tillerson would be the most dramatic example of Trump’s preference for wealthy outsiders like himself among his Cabinet. The one-time production engineer has earned hundreds of millions’ worth of Exxon stock over the years, according to a Washington Post report from earlier this year.