Fifty Shades of Grey director Sam Taylor-Johnson pulls out of sequels

Taylor-Johnson previously directed Nowhere Boy, a film about the young John Lennon

Sam Taylor-Johnson, the director of adult drama Fifty Shades of Grey, will not direct its planned two sequels.

The artist and film-maker said she was "hugely grateful" to have been chosen to adapt EL James's 2011 best-seller.

She then wished "nothing but success to whosoever takes on the exciting challenges of films two and three".

Fifty Shades, about a businessman who begins a sadomasochistic affair with a young student, has made almost $560m (£375m) at the worldwide box office.

EL James's trilogy of Fifty Shades books have reportedly sold more than 100 million copies worldwide and been translated into more than 50 languages.

Relations between Taylor-Johnson and the author were said to be strained during its production, prompting speculation the artist-turned-director would not return to continue or complete the film trilogy.

"We battled all the way through," Taylor-Johnson told Vanity Fair magazine. "She'd say the same. There were tough times and revelatory times. There were sparring contests. It was definitely not an easy process."

Jamie Dornan and Dakota Johnson are expected to return as Christian Grey and Anastasia Steele in the next film, scheduled for release in 2017.

"Directing Fifty Shades of Grey has been an intense and incredible journey," said the director in a statement, first published on the Deadline website. "I have Universal [Studios] to thank for that.

The artist formerly known as Sam Taylor-Wood said she had "forged close and lasting relationships with the cast, producers and crew and most especially, with Dakota and Jamie."