PARIS (AFP) - Star choreographer Benjamin Millepied said on Thursday he was quitting the Paris Opera Ballet after little more than a year in charge of one of the world's grandest ensembles.

The former dancer - who is married to Hollywood actress Natalie Portman - had faced stiff resistance to his plans to radically reform the institution, a bastion of classical ballet tradition.

"I have decided to end my time as director of dance," he said in a statement, adding that he wanted to "concentrate 100 per cent on creating" rather than on administration.

His shock departure came only a day before the world premiere of his latest work at the ballet, ironically titled The Night Ends.

Although Millepied, 38, insisted that "the ties that bind me to this beautiful institution mean that I will always be at its side", his early exit is a major blow to both parties.

As fans bombarded his Facebook page with messages beseeching him to stay, Millepied said: "My functions as director... take up so much time that they have considerably reduced that for artistic creation, which is essential in my view."

One fan Genevieve Renaud wrote, "You gave dance a new breath of air, stay and continue to shake this crusty old lady that has mummified."

The choreographer made his name as a dashing principal dancer at the New York City Ballet before returning in triumph to France in 2014 to head up the Paris Opera Ballet.

But relations with the board appeared to have broken down after he lambasted the way the ballet was run in a documentary aired on the Canal+ channel just before Christmas.

He claimed that the ballet was too hierarchical and set in its ways.

Nor was it any longer as "excellent" as it claimed to be, he said, with dancers sometimes looking like "wallpaper... bored to death".

"I don't think we're in a golden age of ballet right now," he said as his frustration boiled over in another recent interview with a fashion website.

"Even musicals are more daring than new ballets!" he told Style Report.

He was particularly irked by the ballet's lack of diversity and the rigid methods of its school.

"I think it's very important that the company resembles Paris and not the old-school form of racism that ballet companies need to be white," he added.

"I don't have control over the school at this point... If I'm staying long term, I need to have more say on what it means to be a ballet school in the 21st century," he said.

Even as he announced his first season in 2014, Millepied told AFP that the ballet was stuck in the past.

"It is no longer 1830, (yet) there are things from that period like the hierarchy, the rigid internal competition for promotion."

Millepied and Portman met on the set of the ballet-themed 2010 thriller Black Swan, which earned the Israeli-born actress a best actress Oscar for her role as a ballerina driven close to madness by her quest for perfection.

The couple brought a huge injection of glamour, and sponsorship cash, to the venerable Paris institution.

But Millepied's impatience for change grated with some, even as younger members of the company revelled in the opportunities he opened up for them.

More than 100 fans posted heartfelt appeals for him to stay on his Facebook page as the news leaked out.

Many raged against the ballet's "dinosaurs" who they accused of blocking his reforms, while Severine Boutry said: "It's desperate. Even in culture, France is not capable of reform."

The Paris Opera Ballet refused to comment, but has called a press conference at its opulent Palais Garnier theatre later Thursday.