The Culture Ministry said yesterday that it has reached an agreement with a New York philanthropist for the return to Greece of two ancient artifacts which are believed to have been stolen by antiquities thieves. In a statement, the ministry said that Shelby White, who founded the Institute for the Study of the Ancient World at New York University, had bought the items in good faith for her collection of antiquities. The antiquities are a bronze vase and a broken marble sculpture that originally adorned an ancient grave. Both date from the 4th century BC. The marble fragment forms the upper part of a grave marker found in the 1960s during excavations at Porto Rafti, east of Athens. The vase is likely to have been found in an illegal excavation in northern Greece, the ministry said.