Podesta's decision to leave the Podesta Group was announced to the firm on Monday morning, Politico reported, and came a week after it was revealed that the government was investigating whether Podesta violated the Foreign Agents Registration Act, which requires individuals that lobby for foreign entities to disclose activities on behalf of those entities to the Department of Justice.
"In 2012, Manafort and Gates solicited two Washington DC firms (Company A and Company B) to lobby in the USA on behalf of Yanukovych and his party, " the indictment said.
"[Tony] was very magnanimous and said, "This is an incredible group of people", Podesta reportedly told staff he "doesn't intend to go quietly, or learn how to play golf", and that he "needs to fight this as an individual, but doesn't want the firm to fight it".
According to NBC News' report, Mueller's interest in Podesta arose as part of fact-finding about Paul Manafort's work for the Party of Regions: Manafort's longtime business partner, Rick Gates, reportedly directed Podesta's firm's lobbying, as well as the Republican-leaning firm Mercury LLC's lobbying, for ECFMU.
Podesta was the chairman of Podesta Group - a namesake firm that he also founded.
"Manafort repeatedly communicated in person and in writing with Yanukovych, and Gates passed on directions to Company A and Company B", the indictment states. He is the brother of Hillary Clinton campaign chairman John Podesta, who is not under investigation. The Podesta Group was one of several companies paid to work on a PR campaign organized by Manafort to promote Ukraine in the U.S. "They lobbied multiple members of Congress and their staffs about Ukraine sanctions, the validity of Ukraine elections, and the propriety of Yanukovych's imprisoning his presidential rival". Manafort and Gates selected the lobbying firms in February 2012 and the center signed contracts with the firms without ever meeting either one, according to the indictment.
But in the wake of the Mueller investigation the Podesta Group has struggled.
Neither Podesta nor The Podesta Group immediately responded to CNBC's requests for comment.
Manafort and Gates surrendered to the Federal Bureau of Investigation on Monday, as 12 felony counts against the pair were unsealed.