Businessman Carl Icahn departs role advising Trump on regulations

Icahn pushed back on suggestions of impropriety by saying he had "no duties."

In a letter to Trump posted by Icahn to his personal website, he describes the nature of his position as informal, noting he had "no duties whatsoever" -- as opposed to the recently named administrator of the Office of Information and Regulatory Affairs Neomi Rao. In the letter, Icahn further dismisses suggestions that he had the opportunity to personally benefit from the role.

"I never had access to nonpublic information or profited from my position, nor do I believe that my role presented conflicts of interest," wrote Icahn, adding, "I never sought any special benefit for any company with which I have been involved, and have only expressed views that I believed would benefit the refining industry as a whole."

The announcement from Icahn, the founder and majority shareholder of conglomerate Icahn Enterprises, comes days after a number of business leaders resigned from the White House's American Manufacturing Council in the aftermath of Trump's response to last weekend's violence in Charlottesville, Virginia. The American Manufacturing Council disbanded on Wednesday, as did a second, separate panel of CEOs, dubbed the Strategic and Policy Forum.

Icahn's letter made no mention of Charlottesville.

"If Ford or another company announces they want to move their jobs to Mexico or another country, then I will pick up the phone… I will call the executives or I’ll have Carl Icahn do it," Trump said on one such occasion in Michigan in October 2016.

A billionaire, Icahn first began to make his name in the 1980s when he engaged in the earliest of his numerous corporate takeovers by which he accumulated the majority of his wealth.