Fisk University can't sell a 50 percent share in its art collection to Crystal Bridges Museum of American Art in Bentonville, Ark., a Tennessee chancery court judge ruled Friday.

Museum founder Alice Walton, the Wal-Mart heiress, offered $30 million for an undivided interest in the collection.

Ninety-seven works from the Alfred Stieglitz Collection were donated to Fisk in 1949 by Stieglitz's wife, the artist Georgia O'Keeffe, who later gave four more works to the school.

Fisk proposed the joint ownership of its $72 million collection in order to alleviate the school's financial difficulties. One highlight is O'Keeffe's "Radiator Building -- Night, New York," which some appraisers value at $20 million.

The judge ruled that the agreement would violate the terms of O'Keeffe's bequest. Her desire was to "enable the public -- in Nashville and the South -- to have the opportunity to study the Collection," ruled Judge Ellen Hobbs Lyle.