The 33-year-old was supposed to play Christian Grey in the movie adaptation of E.L. James' novel, but because of his busy TV schedule, he had to turn down the role.
A replacement for Hunnam, who features in TV show "Sons of Anarchy", is yet to be named.
Universal Pictures said Hunnam's withdrawal was a mutual decision, reports mirror.co.uk.
In a statement, the firm added that the time the actor had to prepare for the film had been limited by his television work.
To be directed by Sam Taylor-Johnson, "Fifty Shades of Grey" will release in 2014.
--IANS (Posted on 13-10-2013)