BERLIN — A Swiss museum Monday accepted a priceless bequest by the late son of a Nazi-era art dealer, providing a home for long-hidden works by renown masters while also pledging to set a new standard for vetting art looted during World War II.

The decision by the Museum of Fine Arts Bern marks a major step toward resolving the future of one of the most significant art hoards uncovered in recent memory. News of the collection stunned the art world in late 2013, after the German media reported that tax authorities in Bavaria had recovered lost works by Pablo Picasso, Marc Chagall, Otto Dix and other masters more than a year earlier in the Munich apartment of Cornelius Gurlitt.

Gurlitt died in May at age 81. He was the son of Hildebrand Gurlitt, a dealer who had worked with the Nazis to liquidate art, much of which had been seized or bought at fire-sale prices. The younger Gurlitt left the works to the museum in Bern for reasons that remain unclear.

Christoph Schäublin, president of the museum’s board, said Monday that the institution had thought long and hard before accepting the donation. It finally did so only after striking a rare deal with the German government, which simultaneously announced that it would cover the cost of investigating ownership histories and purchase details of the works.

The museum said it would abide by the 1998 Washington Conference Principles on Nazi-Confiscated Art, which lay out guidelines for assessing ownership of and making restitution for artwork. Any pieces found to have been wrested wrongly from Jewish hands, officials said, would be returned to their heirs.

In a significant move, the German government Monday published the war-era sales records and business documents of Hildebrand Gurlitt online, a move that attorneys of heirs have been clamoring for to aid their clients’ claims.

Three pieces in the collection – by Henri Matisse, Max Liebermann and Carl Spitzweg – have been determined to be stolen and will be returned to their rightful heirs, officials said Monday.