NEW YORK (AP) - A Francis Bacon double-panel self-portrait and a Cy Twombly "Blackboard" painting executed in blue - both in private collections for decades - are the top highlights at Sotheby's auction of contemporary art on Wednesday.

NEW YORK (AP) A Francis Bacon double-panel self-portrait and a Cy Twombly "Blackboard" painting executed in blue both in private collections for decades are the top highlights at Sotheby's auction of contemporary art on Wednesday.

The paintings are among 44 artworks going under the gavel during the evening sale.

Bacon's 1970 diptych, "Two Studies for a Self-Portrait," has remained in the same collection for 46 years, having been acquired the same year it was created. The work has been exhibited only twice, once at the Grand Palais in Paris in 1971 and at the Marlborough Fine Art Small Portrait Studies exhibition in London in 1993. It's estimated to sell between $22 and $30 million.

Bacon created only two self-portraits using the double format, one sold last year at Sotheby's for $22.4 million.

The record for a Bacon work is $142.4 million.

Twombly's "Untitled (New York City)" from 1968 is the only composition from his celebrated "Blackboard" series that features blue loops on a gray background. It was acquired directly from the artist and has remained in the same collection ever since.

Sotheby's also is offering another large-scale canvas by Twombly, this one created in 2004 in the last decade of his life. "Untitled (Bacchus 1st Version V)" is executed in blood red swirls and is one of six paintings from his famous "Bacchus" series. It could bring more than $20 million. The auction record for Twombly is $70.5 million, achieved at Sotheby's last November.

Other top lots include Andy Warhol's "Self-Portrait (Fright Wig)." It's the pop artist's last self-portrait, made in 1986 just months before his death. The silkscreen, in which Warhol wears a dramatic silvery gray wig, has a presale estimate of $7 to $10 million.

Among other highlights is David Smith's painted steel sculpture, "Zig 1," and Sam Francis' oil painting, "Summer #1, 1957." Both carry presale estimate of $8 to $12 million.

The sale also includes an Alexander Calder standing mobile that the artist gave Alfred Barr Jr., the founding director of the Museum of Modern Art in New York, in 1966. "Untitled," created in 1942, incorporates found pieces of colored glass and is estimated to bring $3 to $4 million.