The United States will return 42 cartons of dinosaur egg fossils to China under an agreement signed here on Tuesday.

Under the agreement signed by the Consulate General of the People's Republic of China and the U.S. Customs and Border Protection Bureau (CBPB), the United States will release the fossils at a time to be discussed by both sides, said consulate official Huaizhi Chen.

Chen said once transportation arrangements were made, the Chinese side would take over the fossils. Chen refused to give a street value of the fossils, saying such relics could not be valued by money.

Aileen Suliveras, Assistant Port Director at the CBPB, told reporters that the return of the fossils was part of U.S.-Sino cultural cooperation which had extended to various fields over the past few years, including the protection of cultural relics.

She said U.S. customs police seized the fossils in 2001 in a warehouse in the Long Beach Port, about 30 miles south of Los Angeles, and arrested a suspect, an Australian, who bought the fossils at black markets in China and smuggled to the United States via Australia.

Suliveras did not give the exact figure of the fossils but said the cartons consisted of hundreds of fossils. But she said some fossils are real and the others are fake.