A judge yesterday ordered two 15th-century portraits by artist Albrecht Durer, valued at an estimated $10 million, returned to the Kunstsammlungen Zu Weimar Museum in East Germany. The paintings vanished at the end of World War II from a German castle that American troops had been occupying.

The American possessor of the oil-on-wood treasures, painted in 1499, said he would appeal the decision by Judge Jacob Mishler of U.S. District Court in Brooklyn, which climaxed a decade of litigation over their rightful ownership.

"I think this is a wrong decision," said Edward Elicofon, 77, an attorney living in Greenwich Village.

"The judge should have let the case go to trial and let a jury of my peers decide if the paintings belonged to me or to East Germany," Elicofon said.

Elicofon bought the paintings in 1946 for $450 from an ex-GI, whose name was not revealed incourt. Nor was there any indication as to how they came into that soldier's possesson.

The 11 1/2-by-9 1/2-inch portraits, of German nobleman Hans Tucher and his bride, Felicitas, originally hung in a museum in Weimar. In 1943 they were transferred to a castle at Schwartzburg, near Nuremberg, because of Allied bombing.

According to the court findings, officials of the museum checked the vault at Schwartzburg in June 1945 and found everything in good order. However, later than month the German army surrendered and the Allies began to pull out of the area.

German officials said they found the vault at Schwartzburg smashed open and said a subsequent inventory disclosed the absence of the Durer portraits.

Elicofon said he did not learn East German authorities had listed the paintings asmissing until after he had bought them and hung them in his living room.

Word that the paintings were in Elicofon's home leaked out after by a friend of his who realized they were painted by Durer and were on a list of paintings that had disappeared from Germany at the end of the war.

Elicofon refused the East German government's demand for their return, and the suit followed.

The paintings are being held in a Manhattan vault pending the outcome of the case.