ARMONK, N.Y. (AP) _ At age 75, Martha Nierenberg can wait no longer for the Hungarian government to turn over family art treasures looted by the Nazis.

Mrs. Nierenberg, the granddaughter of a Hungarian baron, filed a lawsuit Tuesday demanding that Hungary immediately return the paintings she calls ``the last prisoners of World War II.''

The suit, filed in Budapest, follows three years of unproductive negotiations to recover 10 paintings from Hungary and two of its national museums.

``They kept stalling and stalling and stalling,'' Mrs. Nierenberg said. ``I'm 75 years old and as it is with these things, they were just waiting for me to give up, to go away, to die.''

Sandor Beer, the Hungarian consul in New York, said he had not seen the suit and had no comment.

Mrs. Nierenberg is the granddaughter of Baron Maurice Herzog, who amassed a 2,500-item art collection between the world wars, including paintings attributed to El Greco, Velazquez and Courbet.

The baron died in 1934, dividing his estate among his three children, including Mrs. Nierenberg's mother. The collection has been appraised at more than $20 million.

But in 1944, under the direction of Adolf Eichmann, the best pieces were sent off to Germany as Mrs. Nierenberg's Jewish family fled Hungary, the court papers say.

Most of the art was returned to Hungary after the war. But because Mrs. Nierenberg's mother was in the United States by then, the pieces that had been left to her were sent to the major government museums in Budapest under a ``safekeeping'' law.

The Hungarian government acknowledged that some of the works in its custody were from the family collection, but said it wanted to take no action until the collection could be accounted for as a whole.

Mrs. Nierenberg's lawyer, Glen Young, said Hungarian law was clear. ``She owns the paintings. They were never nationalized by the government, never taken or appropriated.

Mrs. Nierenberg remembers many childhood visits to the baron's home on Andrassy Boulevard in Budapest. ``His house was like a museum,'' she recalled.

``I was there often and I was always a little bit annoyed because I would want to sit down on a chair, and I would hear, `Oh, no, you can't sit down on that chair, that's 12th century,'' she said.