When the Museum of Modern Art's Pierre Bonnard retrospective opens on June 21, two paintings of female nudes -- one rendered in bright yellow, rose and orange, the other in subtle blue and gray -- will be missing, withdrawn from the show by their owners.
One of the collectors said explicitly that he had acted because of the ownership dispute involving two Egon Schiele paintings with a Nazi-clouded past that were borrowed by the Modern for a show that closed on Jan. 4. Soon after the show closed, the Manhattan District Attorney, Robert M. Morgenthau, issued a subpoena ordering the museum to detain the paintings just as it was preparing to return them to the Leopold Foundation in Vienna.
Officials of many museums warned that collectors would decline to lend their paintings as a result of the legal action involving the Schieles. But the Bonnard pictures are the first known works to be withheld because of the dispute.
To the consternation of the Leopold Foundation, the Schiele works, which continue to be the subject of a criminal investigation by the District Attorney's office, are still being held at the Modern. The effects of the controversy are widening in the art world, which has for decades counted on Federal or New York State laws that shield art loans from detention or seizure. Many people are anxiously awaiting a court ruling, expected next month, on the legitimacy of the subpoena, which the Modern moved to quash.
But some museum directors, collectors and even government officials are not waiting to question their age-old practices.
Before the Metropolitan Museum of Art shipped three dozen works by Paul Klee to an exhibition in Berlin recently, museum officials wrote to the German museums that once owned two of them, asking if they had any claims on them, a new precaution for the Metropolitan.
In Washington, the United States Information Agency is for the first time planning to write regulations for the Federal program that protects international cultural loans from seizure.
A task force formed by the Association of Art Museum Directors is working on guidelines for museums confronted with ownership claims for art plundered by the Nazis. And the director of the Modern, which unexpectedly found itself at the center of a debate about World War II's unfinished business, convened a small group of historians, trustees, lawyers, dealers, museum officials and auction house executives in an all-day retreat on the issue at a conference center in Pocantico Hills, N.Y., on April 9.
"I felt after the Schiele dispute that it was very important to step back, not to get caught up in the moment, to think about the larger questions involved in looted art," said Glenn D. Lowry, the museum's director.
So far, while museum officials say privately that collectors have grown apprehensive about lending their paintings, only the Modern has admitted to exhibition casualties -- and only for the Bonnard show, which is currently on view in London.
Of the 84 Bonnard paintings that had been expected, the Modern confirmed that two will not be on view. "They'll be missed," Mr. Lowry said. "But mercifully the anchors of the show are all in place."
The museum declined to name the paintings or the owners, but the works, "Standing Nude" and "Gray Nude in Profile," were easily identified by comparing the exhibition's current checklist and the exhibition catalogue (which matches galley proofs that were available in early February). In the catalogue, the two paintings are each identified as the property of a "private collection," with the added notation of "Principality of Liechtenstein" for "Gray Nude in Profile."
Elizabeth Addison, the Modern's deputy director for marketing and communications, said that the owner of "Standing Nude" gave no reason when the painting was withdrawn a few weeks ago. But the owner of "Gray Nude in Profile" wrote a letter from Vaduz, Liechtenstein's capital, dated Feb. 10, to John Elderfield, the exhibition's curator, saying in part: "The news of the arrest of the two Schiele paintings in your museum made me very anxious and unsure, and you certainly will understand that I'm not in a position to lend you my painting under such circumstances."
The Modern included a copy of the letter, without the author's name, in an affidavit it filed in an attempt to quash the subpoena issued by Mr. Morgenthau's office. For the Schiele exhibition, the Modern did not seek Federal protection, which shields international loans from legal actions, but relied instead on the New York State Arts and Cultural Affairs Law, which covers all art on public exhibition in the state. Mr. Morgenthau argues that state protection, unlike Federal, does not extend to property in a criminal investigation like his.
Mr. Lowry said the Bonnard show, unlike the Schiele show, had been registered for immunity from seizure with the United States Information Agency.
R. Wallace Stuart, the agency's deputy general counsel, said in a phone interview that more museums in and outside New York have sought Federal protection from seizure since the Schiele subpoena, though he could not quantify the increase.
Since the Federal law was passed in 1965, he said, the Government has responded to applications for immunity on an ad hoc basis, without a written policy. Only one or two applications have been denied, he added.
But now an interagency group including the State Department is assessing the program. "We are looking at what we require of museums," Mr. Stuart said. "We're actively discussing how to fulfill the intent of Congress, which was to encourage the exchange of art, and the obvious problem of the appearance of protecting something taken in the Holocaust."
The results will probably come in the form of guidelines to museums about the information that must be provided to the Government. "If an artwork was in Paris in the 40's, we'll be looking at provenance," Mr. Stuart said. "We didn't before."
The agency has not, however, decided what level of scrutiny is necessary to gain Federal immunity. "We don't want to put such an onus on museums that it would reduce the amount of wonderful art available to the people of the United States," Mr. Stuart said, "but we don't want to be in the position of defending something taken during the war."
Heading off such a disaster was also the motive behind the Metropolitan's letters in late March to museums in Mannheim and Essen. Before shipping the Klees to the National Gallery in Berlin for an exhibition beginning on June 24, the museum reviewed their provenance records with more diligence than usual. "We're checking everything," said William Lieberman, the curator of 20th-century art.
During the checks, staff members noted that two works had been in German museums before the war and that one of the two had been confiscated by the Nazis. But both German museums assured the Metropolitan that they had no claim on the works. "It surprised everyone in Germany that we'd bothered to write," Mr. Lieberman said.
Such checks may become routine. "This is an era of scrupulous due diligence, heightened by the Schiele incident," said Harold Holzer, the Metropolitan's spokesman.
Still, no one seems eager to make predictions about ramifications. Participants in the Modern's Pocantico meeting said their discussions had produced more questions than answers, and little agreement on how problems of looted art should be resolved.
"The sorting out of this issue will be a very long process, and will not lend itself to formulas," Mr. Lowry said. "Every single instance is unique, and that means that every single instance has to be dealt with separately."