Botero's 1969 "Man Going to Work" is the top lot in Christie's line-up for its Wednesday sale, with a pre-sale estimate of up to $1.8 million. Matta's "Morphologie Psychologique" could fetch up to $3.5 million at Sotheby's two-day auction on Wednesday and Thursday.
The Latin American auctions follow post-war and contemporary art sales earlier this month in which a Barnett Newman abstract painting called "Black Fire I" sold for $84.2 million, a new auction record for the artist, and Andy Warhol's "Six Self-Portraits," went to the highest bidder for $30.1 million.
"During the first half of May there were practically $2 billion in sales at auction houses in New York of modern, impressionist, and contemporary art, something that seems to never have happened before." said Axel Stein, Sotheby's Latin American art chief.
"There is a contagion of optimism," he added.
Botero's painting, reminiscent of surrealist Belgian painter Rene Magritte's style, shows a corpulent wife and baby waving off a man while a man in the background looks over a garden framed by a volcano and mountains.
"It has the sense of the uncanny such as in a Magritte," said Christie's Latin American art head Virgilio Garza.
Matta's "Morphologie Psychologique" explores how to depict the subconscious at work, Stein said.
The painting's overlapping coats suggest the veiled quality of dreams, while its spasms of color in cellular forms pop like outbursts of thoughts.
"The guy worked in the surrealist mode," said Stein. "He wanted to show the shape of thoughts."
Signature works by Uruguayan Joaquin Torres-Garcia are also on offer, led by his 1931 "Composition TSF," which Christie's estimates will sell for between $1 million to $1.5 million.
His "Grafismo Infinito," from 1937, is valued at $800,000 at Sotheby's. In it, Stein said, Torres-Garcia attempts to create a universal pictograph language, including references to Inca stonework.
Christie's will also offer a set of 12 paintings, dated from 1900 to 1921, depicting charros, or skilled Mexican horsemen and rodeo riders. Painted by Mexico's Ernesto Icaza, the series is valued at up to $750,000.
Christie's expects its sale to total between $15 million to $21 million and Sotheby's anticipates taking in $43 million during its sales.