Bob Mercer, a prominent Trump backer, leaving hedge fund

Republican mega-donor Robert Mercer, a billionaire with close ties to President Donald Trump, is stepping down from his position as chief executive officer of the New York investment firm Renaissance Technologies. The 71-year-old Mercer is also selling his personal stake in the pro-Trump website Breitbart News to his daughters.

He announced his decision on Thursday in a letter to investors that also condemned white supremacists, distanced himself from former Trump strategist Steve Bannon, and declared he was mistaken for supporting alt-right hero Milo Yiannopoulos.

"I have decided to correct some of the misinformation that has been published about me," wrote the 71-year-old Mercer, who cited "a great deal of scrutiny from the press."

The notoriously private Mercer is considered one of the most powerful political benefactors in the Trump era.

After initially backing the presidential bid of Texas Sen. Ted Cruz, he and his daughter, Rebekah Mercer, poured resources into efforts to help elect Trump last fall. They are also major backers of Breitbart News, which is led by Bannon, Trump's ex-chief strategist. The site has been criticized for encouraging white supremacists who make up the so-called "alt-right" movement.

"Of the many mischaracterizations made of me by the press, the most repugnant to me have been the intimations that I am a white supremacist or a member of some other noxious group," Mercer wrote in his resignation announcement. "Discrimination on the basis of race, ethnicity, gender, creed, or anything of that sort is abhorrent to me. But more than that, it is ignorant."

On Bannon, who is now leading an effort to take down congressional Republican incumbents, Mercer wrote that their politics are not necessarily in lockstep.

"I have great respect for Mr. Bannon, and from time to time I do discuss politics with him. However, I make my own decisions with respect to whom I support politically. Those decisions do not always align with Mr. Bannon's," Mercer wrote.

At the same time, he condemned Yiannopoulos, one of Bannon's protégés at Breitbart, who has inflamed racial tensions in a series of provocative speeches on college campuses across the nation.

"In my opinion, actions of and statements by Mr. Yiannopoulos have caused pain and divisiveness undermining the open and productive discourse that I had hoped to facilitate," Mercer wrote. "I was mistaken to have supported him, and for several weeks have been in the process of severing all ties with him."

The development comes as another Mercer-backed company, the data firm Cambridge Analytica, faces new scrutiny for possible links to the federal probe into Russia's meddling in the 2016 president election.

Wikileaks editor Julian Assange told The Associated Press last week that Wikileaks received a "request for information" from Cambridge Analytica prior to the election. Assange would not specify the request, which he said was rejected, but The Daily Beast reported that the head of Cambridge Analytica reached out to Assange during the presidential campaign about the possible release of 33,000 of Hillary Clinton's missing emails.

Those emails have never been publicly released.

Renaissance has also been locked in a years-long dispute with the IRS after a Senate investigation determined that the firm used complex financial instruments to avoid paying nearly $7 billion in taxes.

Mercer said he would formally step down from his leadership role at Renaissance Technologies on Jan. 1.