Rome ? New York’s Metropolitan Museum of Art agreed Monday to return antiquities Italy says were looted in exchange for long-term loans of other artifacts – a precedent archaeologists hope will prompt museums to change their acquisition policies.

The agreement, which is expected to be signed today in Rome by Met chief Philippe de Montebello and Italian Culture Minister Rocco Buttiglione, will likely have ramifications across the museum world, thrust into the spotlight by a vigorous Italian campaign to reclaim treasures it says were illegally taken from its soil.

Antiquities experts and archaeologists said that unless the Met and other museums are forced to change their policies to prevent the acquisition of looted treasures, the Met’s agreement with Italy will be little more than a one-off deal.

“The Italians have the best evidence we’ve ever had in 40 years,” to go after museums with dubiously provenanced antiquities, said Ricardo Elia, an archaeology professor at Boston University. “They can’t just accept a trade. They need to make them change their policy.”

The Met had already announced Feb. 2 it would transfer legal title to Italy of six important antiquities that Italy says were looted, including the Euphronios Krater, a 6th-century B.C. painted vase that is widely regarded as one of the finest examples of its kind.

In exchange, it proposed that Italy provide long-term loans of works of “equivalent beauty and importance.”

The 3rd-century Morgantina silver collection was smuggled out of Sicily. The other four objects involve Greek earthenware treasures dating from 320 B.C. to 520 B.C.

The Met offered to return the items after saying it had received evidence from the Italians about their origins, a breakthrough in a decades-long dispute that highlighted other battles by countries such as Greece and Turkey to reclaim their cultural heritage from tomb-raiders and the museums that do business with them.

As part of the Italian crackdown – and perhaps contributing to the pressure on the Met – a former curator from the J. Paul Getty Museum in Los Angeles, Marion True, is on trial in Rome, accused of having knowingly purchased stolen artifacts for the museum from Italy. True denies any wrongdoing.

Patty Gerstenblith, a professor of antiquities law at DePaul University in Chicago, said the deal with Italy was very significant because the Met was recognizing Italy’s title and ownership rights to artifacts found on Italian soil.

A 1939 Italian law states that any ancient artifact found in a dig belongs to the state.