Sept 9 (Reuters) - Sotheby"s on Thursday announced the sale of a private modern and contemporary art collection featuring Andy Warhol and Pablo Picasso pieces valued at more than $600 million, saying that was the highest estimate ever placed on any collection to come to auction. The 65 works in the Macklowe Collection represent "an unrivalled ensemble that charts the high points of Western artistic achievement of the last 80 years," Sotheby"s said in a press release. "There can be no doubt that this sale will captivate top collectors from around the world and that it will make history as a defining moment in the art market,” said Charles Stewart, Sotheby"s chief executive officer, at a livestreamed press conference on Thursday. The announcement is a welcome piece of revitalizing news for the international art market as it rebounds from the COVID-19 pandemic, which drove down sales and caused layoffs at galleries and dealerships. Sales plummeted in value by 22% in the art market in 2020, according to a report by Art Basel and UBS. A logo is pictured on Sotheby"s in Geneva, Switzerland, June 21, 2020. REUTERS/Denis Balibouse A logo is pictured on Sotheby"s in Geneva, Switzerland, June 21, 2020. REUTERS/Denis Balibouse Real estate mogul Harry Macklowe and his wife Linda acquired the pieces over the course of their decades-long marriage, but a New York judge ordered them to sell the collection and split the proceeds during their 2018 divorce trial. Sotheby"s said on Thursday it would offer the Macklowe Collection at two sales in New York, one on Nov. 15 and the second in May 2022. The first auction will feature iconic works such as Warhol"s silkscreen portraits of Marilyn Monroe, an enormous tritone painting by Mark Rothko, and a seascape by Gerhard Richter. Other distinctive pieces that will be sold in November include Alberto Giacometti"s "Le Nez" sculpture of a long-nosed figure in a cage, a painting from Cy Twombly"s "A Scattering of Blossoms" series, and a Picasso sculpture dedicated to his friend, the French poet Guillaume Apollinaire.