"The Marsh Hawk," by Andrew Wyeth, a 1964 picture of Wyeth's home in Chadds Ford, Pa., yesterday became the most expensive picture by a living American artist ever sold at auction. It brought $420,000 in the New York salesrooms of Sotheby Parke Bernet.

The previous record for a painting by a living American -- $300,000 for "Empyrean," a 1960 Washington Color Painting by Kenneth Noland -- was set Nov. 19 and held less than a month.

"I'm surprised and delighted that someone wanted it so badly," Wyeth said last night. "The Marsh Hawk" shows three wagons ("gifts from a friend," said Wyeth), the painter's farmhouse ("it's called 'Brinton's Mill,' " he said) and an attached barn. The bird of prey is barely visible on the stump at the extreme left.

"The picture," said Wyeth, "was once owned by the late Dr. Margaret Handy. She bought it for $65,000. She also owned my 'Snow Flurries,' a painting now in Washington at the National Gallery of Art."

"The Marsh Hawk," like most Wyeths, strikes a somewhat morbid note. With its leafless trees, withered grass and rusting metal barrel, it suggests nostalgia for a time less frenetic than our own.

The previous record for a Wyeth -- $77,500 for "Moose Horns" -- was set in December 1980. "The Marsh Hawk," done in tempera on masonite, was purchased by an anonymous American collector bidding on the telephone. He actually paid $462,000, since Sotheby's extracts from buyers a 10 percent commission. The consignor also requested anonymity. The underbidder, according to the auctioneers, was a collector in Japan.

"The Thankful Poor," an 1894 oil by the black American painter Henry Ossawa Tanner (1859-1937), sold for $250,000. Tanner, a student of Thomas Eakins, felt subject to racial persecution here and moved to Paris in 1891. "The Grateful Poor," which had been displayed since 1970 in the Philadelphia Museum of Art, was the property of the Pennsylvania School for the Deaf. It was bought by an anonymous American collector.

Other costly objects auctioned yesterday included "Summer in the City," a 1949 oil by the late Edward Hopper, which sold for $300,000 to New York dealer Andre Emmerich; "Portrait of Dorothy," a 1900 oil by John Singer Sargent, which went for $260,000; and "Lily Williams," a portrait by George Luks painted circa 1909, which fetched $235,000.

Sotheby's had estimated that the Wyeth would bring between $400,000 and $500,000. There were 230 lots in the sale of "American Impressionist and 20th Century Paintings, Drawings and Sculpture." They brought a total of $5.7 million.