Rachel Whiteread's "Untitled (Domestic)", 2002 Click photo for larger image.

Joining an emerging trend in the art world, the Carnegie Museum of Art announced its first co-purchased piece of art yesterday, which it bought with an institution in Buffalo.

The Carnegie and the Albright-Knox Art Gallery together bought Rachel Whiteread's large sculpture "Untitled (Domestic)" in a private sale earlier this year. The museums will share the piece year to year -- Albright-Knox unveiled it in August and the Carnegie will get it later this year.

Ms. Whiteread is a leading British contemporary artist who often makes casts of household things such as chairs, bathtubs and tables. The Carnegie already owns "Untitled (Yellow Bath)," a rubber and polystyrene sculpture cast from 1996, and exhibited her "Untitled (One Hundred Spaces)" in the 1995 Carnegie International.

The new piece, from 2002, is 22 feet tall and cast from an interior staircase in a London gallery called the Haunch of Venison, located in a building that was once the home of Adm. Lord Nelson.

The move to buy the sculpture jointly -- a first by both museums -- is increasingly being done by museums nationwide. Last month, the Philadelphia Museum of Art and the Pennsylvania Academy of the Fine Arts joined with foundations and other contributors to jointly buy Thomas Eakins' painting "The Gross Clinic" for $68 million.

The trend is partly a reaction to the skyrocketing prices for contemporary art being paid by individual collectors, which threaten to outpace what nonprofit institutions can pay. During two weeks in November, auction houses Christie's and Sotheby's sold a combined $1 billion in post-war artworks, many of them to private buyers.

Carnegie officials did not disclose what they paid for the Whiteread work, but lately her sculptures -- all of them smaller than the 2002 staircase -- have been going for about $500,000 at auction.

Ms. Whiteread was born in London in 1963. A member of the "Young British Artists" generation, alongside artists such as Damien Hirst, she won the Venice Biennale Best Young Artist award in 1997, the Turner Prize from London's Tate Gallery in 1993 and a Commander of the Order of the British Empire last year by Queen Elizabeth II.

There are also more mundane reasons for co-purchasing art than its price, especially for something as big as this sculpture: Sharing it cuts down on storage and maintenance costs.

The Carnegie will likely place the Whiteread piece in its Hall of Sculpture, the white marble room off the museum's grand staircase.

"This kind of collaboration, the first in our history, opens up many new opportunities for acquisitions in the future," Albright-Knox director Louis Grachos said in a prepared statement.

Carnegie Museum of Art board Chairman William E. Hunt stated the sculpture "is a perfect start for this partnership. Carnegie Museum of Art has long had a close connection with the Albright-Knox Art Gallery and this collaboration helps make it even more tangible and mutually beneficial."