One of Sweden's most significant private holdings of post-war art is heading to the saleroom. Stockholms Auktionsverk has announced that the collection assembled by Anna-Stina Malmborg and Gunnar Höglund will form a central part of its Modern Art Sale, a live auction in Stockholm on 18 November. The couple began buying in the 1960s, when the Swedish capital was closely connected to the art scenes of New York, Paris and the rest of Europe, and they kept collecting with the same curiosity for decades.

The sale's leading lot is Antony Gormley's Iron Baby, a solid cast-iron figure of the artist's daughter at six days old, estimated at 2.5 to 3 million kronor. Its small scale works against the weight of the material, setting the fragility of a newborn against something dense and unyielding. Claes Oldenburg's Pastries, made in 1964 and arranged on a real plate, carries an estimate of 1.5 to 2 million kronor, while Martial Raysse's Femme Leopard is guided at the same range.

Further works include a Christo Store Front estimated at 1 to 1.5 million kronor, a Nana figure by Niki de Saint Phalle, and pieces by Manolo Millares, Antoni Tàpies, Alighiero Boetti and Swedish artists such as Torsten Andersson, Lars Englund, Marie-Louise Ekman and Andreas Eriksson. The couple travelled widely to meet artists and dealers, visiting Cy Twombly in Rome and Andy Warhol at his New York studio in 1981, and they later gave generously to Moderna Museet.

The collection will be on view at the auction house's Nybrogatan saleroom from 6 to 16 November, and the sale will be streamed live. Proceeds will go to foundations set up in the couple's names, which support research in art history and medicine, giving the dispersal a purpose beyond the saleroom.