John Chamberlain, Candy Andy (1963), painted and chromium-plated steel, 37 by 31½ by 27 inches.

A lawsuit by two founders of New York's Dia Art Foundation aims to block the sale of 27 works of art worth as much as $20 million at an auction at Sotheby's on Wednesday.

Heiner Friedrich and Fariha de Menil Friedrich, who established Dia in 1974, filed suit in state court yesterday to stop Dia from selling artwork to form an acquisitions fund, according to a report in the New York Times. The works on offer include examples by John Chamberlain, Cy Twombly and Barnett Newman.

The lawsuit claims that selling the works would remove them "from public access and viewing in direct contravention of Dia's entire intent and purpose," the lawsuit states.

Dia director Philippe Vergne defended the sale in June by saying that "Dia cannot be a mausoleum."

"Dia has always been about the art of our time," a Dia press representative told A.i.A. by phone this week when asked about how the acquisitions fund would be used. "Keeping Dia current is our goal, though there is no specific wish list of works in place."

In July, a June 28 letter to Vergne from Paul Winkler, brother of Dia co-founder Helen Winkler, opposing the foundation's planned sale, became public.

"To sell art works at the core of the ideas and collections of Dia is an outrage and to do so for the purpose of acquiring works by other artists is counter to the unique vision and spirit of Dia," Winkler wrote in the letter.

Representatives of Dia and Sotheby's could not immediately be reached for comment.