NEW YORK (AP)  -- A mural by Mexican artist Rufino Tamayo -- one of five exhibited in the United States still in private hands -- was sold Tuesday for nearly $7 million at a Manhattan auction of Latin American art.

``America,'' measuring 13 feet by 15 feet, fetched $6.8 million, just below its pre-sale estimate of $7 million to $9 million, a spokeswoman for Sotheby's auction house said. The buyer's identity wasn't released.

The lower-than-expected price echoed the slowdown in the art auction market in recent weeks. The buying habits of wealthy collectors have been shifting as they confront the global financial crisis.

In May, Tamayo's ``Troubadour'' sold for $7.2 million at Christie's, setting an auction record for the artist and for a Latin American artwork. Frida Khalo's ``Roots'' had previously held the Latin American record when it sold for $5.6 million at Sotheby's in 2006.

``America'' is Tamayo's biggest mural, said Carmen Meli Dan, director of Sotheby's Latin American art department. It was commissioned in 1955 by the Bank of Southwest in Houston, where it hung until the early 1990s. It was bought by an anonymous private collector in 1993, and has since been on loan at the Dallas Museum of Art.

``America'' is an allegorical work depicting the heritage and cultural richness of the Americas. Its central figure is America, personified by a reclining female nude surrounded by natural resources.

Tamayo, a master colorist, was already regarded as one of the most important artists of his generation when he created the mural in hues of red, green, blue and gold during an especially prolific period.

The auction also included other Tamayo works, including ``Self-Portrait'' from 1931.

Christie's is holding a Latin American art sale on Wednesday that will include another Tamayo painting and works by Torres Garcia and Alfredo Ramos Martinez, among others.

In the past two weeks, many works at Sotheby's and Christie's impressionist, modern and contemporary sales failed to sell or went below their estimates. Some art experts are saying that the lower prices may signal a return to more realistic levels in the fine art market.