MADRID — A Portuguese court has ruled that a former C.I.A. agent should be handed over to Italy after being found guilty by an Italian court of taking part in the kidnapping of an Egyptian cleric in 2003, one of the renditions ordered by the administration of former President George W. Bush.

The former agent, Sabrina De Sousa, holds dual American and Portuguese citizenship. Ms. De Sousa has denied any wrongdoing or involvement in the kidnapping, which took place while she was working undercover for the C.I.A. as a diplomat in Milan. She will appeal this week’s ruling, her lawyer, Manuel Magalhães e Silva, said by email on Friday.

Ms. De Sousa was briefly detained in October at a Lisbon airport after the issuance of a European arrest warrant. The authorities confiscated her passport, but she was freed pending the court’s review of her case.

In 2006, she was among 26 Americans indicted in Italy in connection with the kidnapping of Osama Moustafa Hassan Nasr, a Muslim cleric known as Abu Omar. He was seized in Milan in February 2003.