The Nets did not announce the terms of the deal Saturday, but an NBA official with knowledge of the agreement tells The Associated Press the contract is for $10 million over three years. The official requested anonymity because he was not authorized to speak for the team.
Petro will be a backup for Brook Lopez. Petro averaged 5.1 points and 4.2 rebounds in five seasons with Seattle-Oklahoma City and Denver.
The agreement is contingent on Petro passing a physical.
Petro is a second free agent to agree to a contract with the Nets. Small forward Travis Outlaw got a five-year, $35 million contract Thursday.