By Walker Simon

A rare, life-size, anonymous portrait of Aztec emperor Moctezuma II and a ground-breaking surrealist painting by Chilean artist Roberto Matta are among the top lots in Latin American art auctions next week in New York.

Art experts hope that record sales of post-war and contemporary art this week will have a spillover effect and fuel demand for Latin American art during three days of sales at Sotheby's and Christie's.

"Just thinking of what just happened, of $1 billion of art sold in three short days in New York City is quite a phenomenon," said Axel Stein, head of Sotheby's Latin American department. "We're very interested in seeing what the result of that will be" for Latin American art.

Sotheby's top-priced lots, at between $1.5 million and $2 million, are Matta's 1943 oil on canvas "Nada" (Nothingness) and Mexican Dr. Atl's "Manana Luminosa" (Luminous Morning), a 10-foot (3-meter-wide) 1942 landscape of a semi-arid plateau dotted by snowcapped volcanoes in the distance.

Another highlight at the sale is expected to be a colonial portrait of Moctezuma II, the Aztec chieftain killed by Spanish conquistadors.

The anonymous painting, "Portrait of Moctezuma II," from the final quarter of the 17th century, is expected to fetch at least $1 million. The only other colonial work of the same scale and subject is in a museum in Italy, said Stein.

Matta's "Nada" shows plant-like forms hurling outwards with their stems ringed by sloping rays. A central butterfly-like shape ejects beams in slices of green, red, turquoise and bright sky blue.

"Matta opened a whole new world. He was as interested in what was going on inside matter as he was in cosmic realities," said Stein. "No surrealist had ever gone there, because surrealism had been about how the mind works and what happens in dreams."

At Christie's, the top-priced lot is a bronze sculpture by Colombian Fernando Botero, "Horse," done in 1999, which has a pre-sale estimate of $700,000 to $1 million.

Another Botero work, his 1981 painting "Nun Eating an Apple," will also go under the hammer. Christie's described it as a whimsical representation of original sin showing a portly nun, with a bible in her left hand and the forbidden fruit in her right. Its estimated sale price is up to $700,000.

Mexican master Diego Rivera's "Madre e Hijos" (Mother and Children), is expected to fetch $800,000. Painted in 1926, it depicts a barefoot boy standing next to his sister, who is ensconced in their mother's lap. The children show a gravitas beyond their years.

Christie's estimates its total sales on November 20 and 21 will be between $17.28 million to $23.97 million.

"We look forward to more landmark auction moments for the Latin American sale," said Virgilio Garza, head of Christie's Latin American art department.

Sotheby's expects its sales on November 19 and 20 to total at least $20 million.