Gerard Mortier, the avant-garde artistic director of Madrid's Teatro Real opera house until September last year, has died after battling cancer, the culture ministry has said. He was 70.

Mortier, known for his risk-taking approach to scene work and keen interest in 20th-century opera, commissioned an adaptation of the gay cowboy epic Brokeback Mountain for Teatro Real.

The US composer Charles Wuorinen took six years to complete the opera, and a clearly ailing Mortier attended its premiere in January.

The Belgian prime minister, Elio Di Rupo, led tributes to Mortier, tweeting: "Our country has lost a visionary and generous figure," while the culture minister, Fadila Laanan, said Mortier's "often non-conformist choices, his audacious programming built his international renown".

The Cannes film festival president, Gilles Jacob, hailed Mortier as a "great non-conformist and innovative opera director", and the prominent British music critic Norman Lebrecht called him "brilliant and infuriating".

Mortier won accolades for productions at Teatro Real of Mozart's Cosi fan Tutte directed by the Austrian filmmaker Michael Haneke and Philip Glass's A Perfect American.

Mortier was general director of the Paris opera from 2004 and 2009, and headed the prestigious Salzburg festival from 1991 to 2001.

The Flemish baker's son, who was born in Ghent on 25 November 1943, had gained fame as general director of Belgium's Rola Theatre of the Mint for a decade from 1981.