According to court documents, he has agreed to plead guilty on Friday to two criminal counts in the investigation by Special Counsel Robert Mueller.
Manafort was convicted last month on eight counts of fraud, bank fraud and failing to disclose banks accounts.
It was the first criminal trial arising from the justice department’s probe into alleged Russian election meddling.
However, the charges only relate to Manafort’s political consulting with pro-Russian politicians in Ukraine, largely pre-dating his role with the Trump campaign.
Manafort, 69, was a key figure in Mr Trump’s inner circle, but the president has since sought to distance himself from his former adviser.
The charges in the second trial were set to include money laundering, conspiring to defraud the US, witness tampering and failing to register as a foreign agent. Jury selection was due to start on Monday.
According to the court documents cited by US media, Manafort will plead guilty to one count of conspiracy against the US and one count of conspiracy to obstruct justice when he makes a court appearance on Friday.
In the first trial, Manafort was accused of using 31 foreign bank accounts in three different countries to evade taxes on millions of dollars.
Prosecutors presented evidence of Manafort’s luxurious lifestyle, saying it was only possible because of his bank and tax fraud.
President Trump has branded the Mueller investigation a “witch hunt” and insisted there was no collusion between his team and Russia.
Will Manafort now help Mueller probe?
Analysis by Anthony Zurcher, BBC News, Washington
Paul Manafort’s convictions from his trial in Virginia already guaranteed he was going to prison for an extended period of time. Given that the prospect of the long-time Washington lobbyist walking away from all this a free man had been eliminated, the result opened the door for a plea agreement in his second case, sparing him further legal expenses and giving the special counsel’s office the opportunity for another quick victory.
The political fallout will take longer to assess. Much depends on whether Mr Manafort has agreed to provide any information relevant to the central thrust of Robert Mueller’s investigation into possible Trump campaign ties to Russia during the 2016 presidential election. If he’s on board, this is a blockbuster development. Otherwise, despite the adverse outcome for the former Trump campaign chair, there is a silver lining for the president.
This eliminates a trial that would drag on toward the November mid-term elections, reminding voters of the corruption of a man Mr Trump chose to put at top of his campaign. More than that, it reduces the possibility of the president feeling compelled to say, or tweet, something about the case that could prove embarrassing or potentially damaging to him or his allies.