ROME — A former undercover C.I.A. agent will be handed over to Italy, where she was convicted of taking part in the 2003 kidnapping of an Egyptian cleric in one of the renditions ordered by the George W. Bush administration, after appellate courts in Portugal, where she lives, turned down her appeal this week.

In January, a Portuguese court ruled that the former agent, Sabrina De Sousa, should be handed over to Italy, but the order was stayed pending appeal. On Friday, her Italian lawyer, Dario Bolognesi, said in an interview that the appeal had been denied, and that Ms. De Sousa would be extradited after May 4.

News that Portugal’s Constitutional Court had turned down her appeal this week was also reported on Friday by The Washington Post and by the Portuguese newspapers Diário de Notícias and Expresso. Her Portuguese lawyer, Manuel de Magalhães e Silva, did not respond to requests for comment.

Ms. De Sousa, who holds dual American and Portuguese citizenship, 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 resigned from the agency in 2009 and avoided trial by leaving Europe, but was convicted in absentia that year. Despite the risk of arrest, she returned to Portugal last year to be closer to her family.