Joseph Parker has signed a three-fight deal with Matchroom Boxing ahead of a June 29 fight in the United States.
The former WBO heavyweight champion has taken promoter David Higgins with him after his contract with Duco Events expired.
Parker (25-2) will make his Matchroom bow on the undercard for Demetrius Andrade's WBO middleweight title defence against Maciej Sulecki in Providence, Rhode Island.
He said: "Since my contract with Duco ended, I have been a free agent.
"My team and I [have been] spending several months assessing how to best achieve my goal of not only becoming a world champion again, but unifying all of the belts to become the undisputed heavyweight champion of the world.
Welcome to the Matchroom team, @joeboxerparker!— Matchroom Boxing (@MatchroomBoxing) May 31, 2019
Next out June 29, Providence!
"Ultimately we decided that the best option was to partner with Eddie Hearn and Matchroom Boxing.
"We believe the three-fight deal that we are announcing today will be the start of a long and successful partnership."
Matchroom chief Eddie Hearn added: "If Joseph Parker performs the way we all know he can over these next three fights, he will have a strong case for some huge fights.
"Parker is a young man with a great mix of experience and ambition, and this is a really exciting signing for Matchroom."
Parker lost his WBO belt to Anthony Joshua in March 2018, before being beaten by Dillian Whyte in his next fight.