Frank O. Gehry, the award-winning contemporary architect whose unconventional designs have often become tourist attractions in themselves, has been selected by the Corcoran Gallery of Art to design an addition for its century-old building.

The location, 200 yards from the White House on a prime corner of the Ellipse area at 17th Street and New York Avenue NW, is one of the most prominent in the city.

Gehry's approach -- his Guggenheim Museum Bilbao in Spain, which opened in 1997, has been one of the most talked-about designs in recent years -- would be a break from the existing monuments in heart of the city and an abrupt change from classical feel of the old Corcoran and the heft of nearby landmarks, including the Old Executive Office Building and Constitution Hall. Such departures from the city's traditional look have generated criticism in the past.

But the traditional has not been the 70-year-old Gehry's signature. For the Corcoran competition, he submitted an early concept that dresses the exterior with tumbling arcs, reminiscent of his Bilbao design, that appear to have both a vertical and horizontal flight path and billow above the present Corcoran roof and balloon along New York Avenue. The inside would have a number of canyons, full of air and light, that the selection committee admired.

David C. Levy, president of the Corcoran, said Gehry was chosen because of his originality and respect for the functions and history of the two existing spaces:

"Frank looked at this building as a totality. In his presentation, instead of saying `Here is my building,' he started in the basement and worked his way up. Then he said, `Here is how we will enclose these spaces.' "

Levy is expected to announce Gehry's selection at a news conference tomorrow.

The Gehry submission that got the nod is only a preliminary vision. Now the architect will work with Levy, the art school faculty and administration and other parties to perfect the design.

"I would like it to have that kind of energy and presence," Gehry said yesterday by telephone from Prague. "It's a starting point, and I am not married to any of the images."

Levy added that nothing has been decided: "There are a lot of open questions, how will it be clad, what color will it be."

Washington will likely be a tough audience, the architect admitted. "At first I resisted it. I was worried about Washington," he said. "But David Levy is one of those extraordinary people. He is a strong-willed, intelligent guy who knows what he wants." The final design will have to be approved by the Commission of Fine Arts, but since the Corcoran is a private enterprise there will be less red tape than usual.

The selection committee said the new wing had to be respectful of existing Corcoran landmarks but also create a forward-thinking work of art. The committee was mindful that the dramatic lines of I.M. Pei's National Gallery East Building and Maya Lin's Vietnam Veterans Memorial have attracted many visitors.

The Corcoran space is an unusual configuration, tucked in an angle formed by the original 1897 building designed by Ernest Flagg and the 1928 addition by Charles Platt. An office building occupies the west end of the block. The Gehry design will go over the roof of the present structures, which are well below the city's 90-foot height limit.

The new wing will house the Corcoran's art school and provide room for an expanded children's education center. Officials want to reclaim 19 galleries on the upper levels of the existing buildings that are now largely storage rooms. That would double the exhibit space at the Corcoran, the city's oldest art museum. There will be additional office space and an underground parking garage.

The design process is expected to take a year. The cost of construction, which will probably start in 2001, is tentatively estimated at $40 million.

Gehry, a native of Toronto, has lived in the United States, principally California, since 1947. Over nearly four decades he has built a series of notable private and public buildings across the country and in Europe and Asia. In 1989 he was awarded the Pritzker Architecture Prize, the field's highest honor, and this year he received the coveted Gold Medal of the American Institute of Architects, an organization that has given his buildings many regional and national awards. In 1998 President Clinton awarded Gehry the National Medal of Arts.

His previous work in the Washington area dates from an earlier, more traditional period, and includes the headquarters for the Rouse Co. in Columbia and the Merriweather Post Pavilion.

His vocabulary is not Corinthian columns but the complex geometry of slopes and curves, folded in unusual materials and sometimes unusual colors. Though off the beaten path of Europe's most famous museums, his design in Bilbao, Spain, has been acclaimed as one of the most important buildings of the past 25 years and has turned around the economy of a dying seaport town. That museum has the appearance of a sailing ship covered in titanium, which sends off rays of silver, gold and blue.

His Nationale-Nederlanden building in Prague was derided and nicknamed the "Ginger-Fred house" (after Rogers and Astaire), not only for Gehry's Los Angeles connections but because it seemed to be clad in a twirling skirt, a jarring contrast to the neighboring medieval town houses.

Another avant-garde Gehry edifice, the Experience Music Project, is under construction in Seattle, just north of the landmark Space Needle. The 140,000-square-foot interactive museum, dedicated to popular music, is another series of red, gold and silver flying walls. And in Chicago, even though the exact design is not final, Gehry's selection as the architect for a lakefront music pavilion has sparked comment; some local architects consider him a carpetbagger intruding on the turf of famed builders.

The Corcoran reviewed the work of more than 200 architects during its year-long selection process. The other finalists were Polish-born Daniel Libeskind, perhaps best known for his Jewish Museum in Berlin, and Santiago Calatrava of Spain, who designed some of the buildings used in the 1992 Olympics in Barcelona.

CAPTION: An "early concept" rendition of Frank Gehry's design for a $40 million addition to the century-old Corcoran Gallery of Art.

CAPTION: "It's a starting point, and I am not married to any of the images," Frank Gehry says of his proposal.