In a personal appeal to the Museum of Modern Art, the family of a Jewish Viennese art dealer whose prized painting by Egon Schiele was taken from her by the Nazis before World War II has asked the museum to keep the painting in New York when its exhibition "Egon Schiele: The Leopold Collection" closes on Sunday.
The family wants the museum to retain the painting, "Portrait of Wally," even though it and the other works in the show, which belong to an Austrian Government-financed foundation, are indemnified against seizure, making retention uncertain, if not unlikely. A second family whose relative lost a Schiele work during the war has also asked the museum to hold onto the work until provenance can be determined.
Supporters of the families are hoping that the appeals will prompt the museum's chairman, Ronald S. Lauder, a former United States Ambassador to Austria who is also chairman of the World Jewish Congress's new commission to recover art taken from Jews before and during World War II, to intervene and broker a settlement.
"We must stop the painting from leaving the country," said Henry S. Bondi, a nephew of Lea Bondi Jaray, who died in 1969 without recovering Schiele's 1912 "Portrait of Wally" or getting any compensation for it.
In a letter faxed late on Tuesday to Glenn D. Lowry, the director of the Modern, Mr. Bondi wrote: "We earnestly request that you do not return the painting to the jurisdiction of the 'lenders' until the matter of true ownership has been clarified." Mr. Bondi, who lives in Princeton, N.J., was acting on behalf of Mrs. Bondi's other heirs, who live in New York City, Washington state and Britain.
Mr. Lowry was out of town and unavailable for comment yesterday. But the museum's assistant general counsel, Stephen Clark, confirmed that the letters had been received.
"We are very sympathetic to the two families and their claims," he said. "Our difficulty is that there are competing interests, and we have a contractual obligation with the Leopold Foundation to return these pictures. We are studying this, and we are not sure what we are going to do." The Austrian foundation is named for Dr. Rudolf Leopold, who amassed the world's most comprehensive collection of paintings by Schiele, the Austrian artist, about 250 in all.
Mr. Clark stressed that the owners of art would not lend their works if they had no assurance that they would get them back. "If we can't honor our contracts, it will have the iciest chilling effect on loans," he said. "Who would lend knowing that the pictures might not come back?"
The Holocaust Art Restitution Project, a group started this fall by the B'nai B'rith Klutznick National Jewish Museum in Washington to document Jewish cultural losses, has joined the families' efforts. Yesterday, Marc J. Masurovsky, the project's executive director, sent a letter to the Modern through its general counsel and to members of the Modern's board, including Mr. Lauder, bolstering the two families' request. He offered help in resolving the ownership problems.
"Lauder should do the right thing and hold onto the paintings until the issue is clarified," Mr. Masurovsky said. "This is potentially an international incident, and we don't want that to happen."
Dr. Leopold, a 72-year-old Viennese ophthalmologist whose collection includes "Wally," began buying art in 1950. Over the years he amassed some 5,400 works. In 1994, his holdings were purchased by Austria, and put in the private foundation, which is building a museum in Vienna.
The clouded past of "Portrait of Wally" was described last week in an article in The New York Times that outlined Dr. Leopold's intense collecting activities. After the war, "Wally" was confiscated from the Nazi art dealer who had taken it from Mrs. Bondi and became part of the Austrian National Gallery's collections. Dr. Leopold procured it in 1954 in a trade involving several paintings. In a telephone interview in mid-December, he said he bought "Wally" legitimately.
The provenance of other works in the Leopold Collection has also been questioned as potentially tainted by Nazi plundering. This week another case surfaced, involving "Dead City," a 1911 landscape that is also on view at the Modern. Yesterday, Kathleen E. Reif and Rita Reif, the heirs of Fritz Grunbaum, also wrote Mr. Lowry seeking postponement of its shipment to Europe, where the collection is scheduled to go on view in Barcelona in February. They sent a copy to Mr. Lauder.
Demanding the return of "Dead City," the Reifs wrote: "This painting was taken from Mr. Grunbaum's collection without his consent by Nazi agents or collaborators, after his arrest in Vienna following the Nazi annexation of Austria in March 1938. Mr. Grunbaum died in the Dachau concentration camp. At no time have the surviving heirs of Mr. Grunbaum ever consented to any sale or transfer of the painting."
Rita Reif is a former reporter for The New York Times and still contributes a column for the paper.
Officials of the Austrian National Gallery and the soon-to-be-built Leopold Museum could not be reached for comment on New Year's Eve. But Willi Korte, a stolen-art investigator in Maryland who is assisting the two families, said he spoke early this week with Klaus A. Schroder, the managing director of the Leopold Museum.
"Mr. Schroder said they will have a special board meeting next week, when they will discuss the problems of the Bondi painting," he said. "He said he thought the case should be investigated thoroughly, but at the same time he said that the Austrian Gallery's records showed there was nothing wrong." The conversation took place before Mr. Korte was aware of the Reif claim.
And late yesterday, Mr. Schroder also telephoned Constance Lowenthal, the director of the Commission for Art Recovery of the World Jewish Congress, the panel of which Mr. Lauder is chairman. The commission might get involved, she said, although it does not go into business until mid-January, and Mr. Schroder has asked Ms. Lowenthal to support the Leopold Foundation's effort in finding out the truth about the Bondi painting's ownership.
"These cases have moved to the top of our priority lists," Ms. Lowenthal said.
She said that she had not yet seen any paperwork on the Reifs' claim, but was reviewing the Bondi family's documentation "with a view to determining our course of action, and it is voluminous and complex." Mr. Lauder, she said, declined to comment until the commission had taken a position on the cases.
Of the two cases, Mrs. Bondi's has the more thorough documentation. After the war, she tried many times from her home in London to reclaim "Wally." Although she never filed a lawsuit seeking its return, she wrote many letters to lawyers in Vienna, and she sought help from Otto Kallir, a Viennese dealer who also fled the Nazis and who owned the Galerie St. Etienne in Manhattan. Dr. Kallir, who compiled catalogues raisonnes of Schiele's works in 1930 and 1966, offered to serve as a witness to her ownership of the painting, letters from the 1960's show.
Mrs. Bondi also asked for help in retrieving "Wally" from Dr. Leopold, who had come to London in search of works by Schiele, Gustav Klimt and other artists. In return, she promised to help find drawings and other works by Schiele for him in London, where she owned St. George's Gallery. Dr. Leopold ignored her pleas for the return of "Wally."
"The problem was, she trusted Leopold," said Ruth Rozanek, a niece of Mrs. Bondi who lives in Bellevue, Wash. "There were financial constrictions that didn't allow her to sue. But she should have sued."
In December, Dr. Leopold said that Mrs. Bondi never spoke with the Austrian National Gallery, whose officials told him they had bought the painting from Robert Rieger, another Jew who had fled Vienna. But before he died in the early 1990's, Mr. Rieger said neither he nor his father, a famed collector, ever owned "Wally."
"It's obvious that someone misrepresented this," said Mr. Masurovsky. "The painting seems to belong to the Bondis, and there was a chain of deceit since 1938."
Circumstances surrounding "Dead City" are less clear. According to the catalogue for the Modern's exhibition, the painting passed from Mr. Grunbaum to the Gutekunst & Klipstein gallery in Bern, Switzerland, then to the Galerie St. Etienne in Manhattan, then to Dr. Leopold.
In their letter, the Reifs asserted their ownership, adding, "To the extent the Museum of Modern Art or Dr. Leopold (his family, or any corporation, foundation, or other entity with which he is associated) claims to have title to or right to possession of the painting, we ask that you inform us fully of the facts and circumstances on which that claim is based, so that we can evaluate that position." It asked for a response no later than tomorrow.
The Reif case is a thorny one, because it is unclear what Dr. Leopold or the painting's previous owners knew about its history, said lawyers who specialize in art matters. But in the American legal system, even good-faith purchasers of stolen art do not have title to it.
The courts have held that rightful owners must make timely claims for artworks, although what is timely in cases like these is debatable. "The issue should not be who filed claims when," Mr. Masurovsky said. "You have to ask what happened and try to fix it and not cling to technicalities. We want an amiable agreement that would ideally cede the paintings to the heirs and at least engage in direct discussion with them."
To add to the moral and public pressure, members of the Bondi family have also written to government officials, including Gov. George E. Pataki of New York and Senator Alphonse M. D'Amato, for help. A spokesman for Mr. Pataki said that the Governor has asked his legal counsel to review the Bondi letter and determine what, if anything, he could do to help.
Photos: Ruth Rozanek with a portrait of her aunt Lea Bondi Jaray, a Vienna art dealer. (Rex Rystedt for The New York Times); Mrs. Bondi's heirs urge the Museum of Modern Art not to return Schiele's "Portrait of Wally," right, to the lender. (Museum of Modern Art)(pg. E1); Henry S. Bondi, right, is trying to recover a painting once owned by his aunt Lea Bondi Jaray, shown in 1962. (Edward D. Rozanek (left); Frank Dougherty for The New York Times)(pg. E20)