(BANG) -'Brokeback Mountain' is to become an opera. The Oscar-winning film, which starred the late Heath Ledger and Jake Gyllenhaal, is to be adapted by New York City Opera.

Composer Charles Wuorinen, who is working on the show, said: "Ever since encountering Annie Proulx's extraordinary story I have wanted to make an opera on it, and it gives me great joy that director Gerard Mortier and New York City Opera have given me the opportunity to do so."

The opera is expected to open in time for the New York City Opera's 2013 spring season.

'Brokeback Mountain' tells the story of two male ranch hands who fall in love and documents their hidden relationship over a 20-year period.

Ledger, who received an Oscar nomination for his role as Ennis Del Mar in the film, tragically died of an accidental overdose in January aged just 28.

His posthumous performance as 'The Joker' in new Batman adventure 'The Dark Knight' can be seen this summer. (C) BANG Media International