Donald Trump will turn over some documents to New York's attorney general for her civil probe into his business practices, but need not answer questions under oath while he appeals a judge's order that he testify.
The developments are part of an agreement on Thursday between the former US president, his oldest children Donald Trump Jr and Ivanka Trump, and Attorney General Letitia James.
They followed a 28 February ruling by Justice Arthur Engoron of a state court in Manhattan that James could enforce subpoenas for the Trumps' testimony and documents from Donald Trump, after having found "copious" evidence of possible financial fraud.
The Trumps appealed on 28 February.
James' three-year probe and a parallel criminal probe led by Manhattan District Attorney Alvin Bragg have focused on whether the Trump Organization misstated the values of its real estate properties to obtain favourable loans and tax benefits.
The Trumps have denied wrongdoing, and none has been accused of criminal wrongdoing.
Thursday's agreement, which Engoron approved, requires Donald Trump to comply "in full" with James' subpoena for documents and information by March 31.
It also requires the Trumps to submit for questioning within 14 days if the state Appellate Division rejects their appeal, unless that court or the state's highest court puts the case on hold.
Both sides will speed up the appeals process, with briefing completed by 31 March.
In their appeal, the Trumps have said testifying in James' probe would violate their constitutional rights because their words could be used against them in Bragg's criminal probe.
Donald Trump, a Republican, has accused James of prosecuting him in a "witch hunt" because she opposes his politics, and accused state judges of bias against him.
James and Bragg are Democrats. The attorney general joined the criminal probe last May.