Paul Manafort, President Trump’s former campaign chairman, is forfeiting an estimated $22 million worth of real estate in New York — including three Manhattan apartments, a Brooklyn townhouse and a home in the Hamptons — as part of a plea deal with federal prosecutors announced on Friday.

Under the terms of the deal, Mr. Manafort agreed to tell all he knows to the special counsel, Robert S. Mueller III, who is investigating Russian interference in the 2016 election.

Mr. Manafort, 69, said he would turn over to the government the five properties in New York, including an apartment in Trump Tower, as well as the contents of three bank accounts and his life insurance policy.