NEW YORK, NOV. 6 -- The contemporary art market took a strong slide tonight at Sotheby's, erasing gains of the past two seasons. Sales hit $19.8 million, only half of their lowest estimate by the auction house.

More lots went unsold than sold, with 43 of the 77 works failing to reach their minimum prices.

Casualties would have been heavier if reserves -- the confidential minimum prices accepted by consignors -- hadn't been adjusted in the days before the sale.

"It was not a triumph, but the market seems alive and well," said David J. Nash, Sotheby's director of fine arts, moments after the sale. "We've been through recessions before. We hope people's expectations will be more realistic next time around."

"We were shooting at a moving target," commented John Marion, chief auctioneer and chairman of Sotheby's North America, explaining the difficulty in estimating artworks in a shifting market.

The top-rated lot of the sale, Robert Rauschenberg's pop art-era "Third Time Painting," from 1961, with a large, square-faced Bulova clock imbedded in the center of the canvas, sold for $3.08 million. The clock works and accurately registered the time of its sale at 8:17 p.m.

Viewed as a self-portrait with the clock face -- mounted sideways -- representing the artist's head, the figure continues with a stiff and paint-spattered shirt pinned below it. An ominous chain hangs from the clock. It is a strange necktie, tied to a jagged end of a broken Coca-Cola bottle top. The picture was consigned by the art book publisher Robert E. Abrams.

With a presale estimate of $4 million to $5 million in its glossy catalogue, Sotheby's took the unusual step of lowering that figure to $3 million to $4 million during the preview week.

"We wanted to play it safe with a more conservative estimate," said Lucy Mitchell-Innes, Sotheby's contemporary art expert. That strategy apparently worked.

The record for a Rauschenberg still stands at $6.3 million, set at Sotheby's two years ago when "Rebus," another vintage "combine" painting, sold.

Among the many major casualties tonight, Andy Warhol's blue-tinted "Self-Portrait" in four panels failed to sell and was bought in at $600,000, short of its low estimate of $800,000. The blown-up photo-booth portraits -- silk-screened onto canvas -- show Warhol in dark glasses and skinny tie.

The Warhol was purchased in 1964 by the current consignors, Florence and Brooks Barron of Detroit. It was one of 16 works offered tonight from their collection.

Another Barron lot, Frank Stella's early and apparently autobiographical abstraction "Mary Lou Loves Frank," sold for $594,000. The artist was 22 and just out of Princeton when he completed the green-and-black striped painting in 1958.

Stella was deeply influenced by the paintings of Jasper Johns that he had seen in New York that year at the Leo Castelli Gallery. Ironically, Johns was at Sotheby's Monday evening during a preview of the sale and was observed looking intently at the Stella.

Johns's illusionistic canvas "Untitled" from 1984 was another casualty tonight. It carried a presale estimate of $2.5 million to $3 million and was bought in at $1.4 million. The painting, part of a series, is based on images of the artist's bathroom.

Just four paintings sold for more than $1 million, and two artist's records were set.

A year ago Sotheby's sold a record $98.3 million of contemporary art with just six of the 74 lots going unsold during the peak of the auction boom.

Tonight's sale also trailed last May's results when Sotheby's sold $55.8 million worth of contemporary art and registered a steep buy-in rate of 36 percent. The statistics tend to verify the overall contemporary picture that the market has softened and is seeking stability at lower levels. Wednesday evening's sale at Christie's will sharpen the picture of how dark the market is.

On the European front of painters, Jean Dubuffet's traffic-hopping street scene "Maison Fondee" from 1961 sold for $2.64 million, the second highest lot of the evening. It carried a presale estimate of $2.5 million to $3 million and was guaranteed by Sotheby's, meaning the auction house pays the consignor a prearranged minimum for the picture regardless of how much it sells for -- or if it sells. This policy lessens the risk to the seller but substantially increases that to the auction house, especially in a nervous market.

Another Dubuffet, the 1954 "Cows in a Pasture," is even more charming and humorous than his big city picture and sold for $2.25 million. It too carried a guarantee. The same picture sold at Sotheby's in 1981 for $170,500. Both pictures went to Chicago dealer Richard Gray.

The fourth painting that topped the $1 million mark was Cy Twombly's densely scribbled chalkboard painting, which sold for $1.98 million.

The elegantly minimal triptych "Moon I" by Brice Marden (one of the younger -- and still living -- artists in the sale) snared $880,000. It was estimated to bring $800,000 to $1 million. Mardens have sold on the private resale market for as much as $2.5 million, according to Mitchell-Innes.

Terry Winters's philosophic landscape "Theoprastus' Garden" set one of the two artist records this evening, selling for $148,500.

In a slew of buy-ins a number of younger artists, including Julian Schnabel, Elizabeth Murray and Eric Fischl, failed to sell.

At the high end of living "masters," Roy Lichtenstein's push-button aerosol can "Spray II" got stuck at $600,000 and was also bought in.

"What was lacking tonight were the two stags locking horns," said 57th Street dealer Andre Emmerich. He was referring to the phenomenon of two collectors fighting over a work of art. Emmerich bought Hans Hofmann's "Flaming Earth" for $440,000.