Petrac, who on Tuesday requested political asylum in Greece, will appeal the decision on the extradition with the Greek Supreme Court, said his Greek attorney Alexis Kougias.
The Croatian authorities consider Petrac an important link and probably the chief financier in a network of people assisting Croatian war crimes fugitive Ante Gotovina, who is wanted by the Hague tribunal.
Petrac was arrested in the Greek port of Igoumenitsa for possessing a fake passport. An Interpol warrant had been issued for his arrest because he had been on the run for 18 months after a Croatian court sentenced him to six years in jail for kidnapping.