WASHINGTON (WASHINGTON POST) - Former Exxon Mobil chief Rex Tillerson has reached a retirement deal with the oil giant worth about US$180 million (S$259 million) that would sever his ties with the company if he is confirmed as Mr Donald Trump's secretary of state.

Under a deal reached with Exxon's board of directors, the value of roughly 2 million deferred Exxon Mobil shares that Mr Tillerson would have received over the next decade would be placed in an independently managed trust account, the company said in a statement late on Tuesday (Jan 3).

The arrangement, which Exxon said was struck in consultation with federal regulators, may address some concerns raised by congressional Democrats over the longtime energy executive's financial ties to a company with business operations across the globe. But the Exxon deal does not appear to resolve additional concerns over the breadth of financial information, including full tax returns, sought by Congress ahead of a confirmation hearing tentatively scheduled for next week.

Mr Tillerson's extensive business ties to world leaders, including Russian President Vladimir Putin, are expected to be a focus of the hearing.

The proposed trust cannot hold Exxon stock, and Mr Tillerson has committed to selling the more than 600,000 Exxon shares he owns, the company said. He also agreed not to work in the oil and gas industry for 10 years.

He would give up cash bonuses and other benefits worth about US$7 million, Exxon said.

Mr Tillerson retired a Exxon's chief executive on Dec 31, weeks after he was announced as Mr Trump's dark horse pick to become the country's top diplomat.