WASHINGTON – Issuing an impassioned defense of the role of museums in preserving cultural history, the director of the Metropolitan Museum of Art yesterday sought to refute the arguments of what he called a small group of “radical” archaeologists who say museums’ acquisitions of antiquities contribute to the looting of ancient sites.

The Met chief, Philippe de Montebello, also for the first time extended an olive branch to his staunchest critics, calling for a meeting of museum directors and the leaders of the Archaeological Institute of America to hash out a resolution to what has become a very public dispute over cultural property.

“I invite the leadership of the AIA to engage with museums in a civil discourse in good faith, in an open dialogue, to resolve our differences,” Mr. de Montebello said yesterday in a speech at the National Press Club. “We should do so for the benefit of the world’s cultural and artistic heritage, which are more likely to be preserved if we have a united agenda for the advancement of knowledge.”

Museum directors and some of the nation’s leading archaeologists will gather in New York next month for a major symposium on cultural property issues being organized by the Association of Art Museum Directors. However, Mr. de Montebello said after his talk that he hopes to meet with AIA leaders in a private setting.

Mr. de Montebello’s address was his first formal speech since striking an agreement in February to return disputed antiquities to Italy in exchange for long-term loans of equivalent objects. The pact came after months of negotiations with Italian cultural officials, and amid ongoing trials and investigations by the Italians into an allegedly vast network of illicit trading of prized ancient artifacts, many of which they say were looted from what is now Italian soil. An American dealer, Robert Hecht Jr., is on trial in Rome for conspiring to traffic in stolen art, as is a former curator at the J. Paul Getty Museum in Los Angeles, Marion True. Both deny the charges. An Italian dealer, Giacomo Medici, was convicted of selling looted art in 2004.

Several other American museums are now the subject of claims by Italy, Greece, and Egypt. Citing similar collecting practices at museums across Europe, the Met director said he wondered why it seemed only American museums were being targeted.

In his speech, Mr. de Montebello tried to reach out to critics in the archaeological community even as he denounced their principal claims. “They believe and proclaim that all collecting, especially in the United States, is the reason there is so much looting of sites. It’s not. That all objects without clear pedigree are looted. They are not,” he said. “And they condemn not just the looters, as it should be, but the objects themselves, which are called tainted and which almost without exception they would not publish, thereby suppressing valuable knowledge.”

In harsh terms, the Met director rejected the notion that objects with no known provenance – often called orphans – should be condemned to obscurity. “As archaeologists have said, these unprovenanced objects are orphans, as their parentage, through the absence of a known find spot, is lost. But would these same archaeologists abandon a shivering orphaned child on the cold rainy day in the street?” Mr. de Montebello said. “We museums are the orphanage of these objects.”

Despite Mr. de Montebello’s invitation for a meeting, his strong language seemed to curry little favor with the president of the AIA, Jane Waldbaum, a prominent critic of museum policies who will appear at next month’s forum. While she said she was open to talking, Ms. Waldbaum did not commit to a meeting and said that if Mr. de Montebello really wanted a civil discourse, he should “tone down the rhetoric.”

Responding to Mr. de Montebello’s comparison of museums to orphanages, Ms. Waldbaum said, “Shivering orphaned children don’t usually fetch million-dollar prices.”

Ms. Waldbaum also disputed Mr. de Montebello’s contention that only a “small, but rather radical and vocal group” of archaeologists shared the AIA’s view on the acquisition of antiquities. She said the institute’s rules on publishing unprovenanced objects, which date to 1973, were voted on by members, and she cited similar policies by other organizations, such as the Society for American Archaeology.

Mr. de Montebello said it is impossible for American museums to be encouraging a black market in antiquities because they buy – and are offered – very few of them these days due to tightened acquisitions policies and cultural property laws. The countries claiming ownership of pieces originating from their soil, he said, should combat the black market not by targeting museums but by creating a legal market for the trade of antiquities.

While he said the purchase of questionable antiquities was a “closed chapter” for American museums, Mr. de Montebello offered something of a mea culpa for the past. He acknowledged that officials at major museums, in their “natural eagerness” to build up their collections, had fallen prey to “very clever imposture and deception” by dealers who traded illegally in antiquities. He said he counted himself among those officials. “I was duped, too,” he said later.