Alec Baldwin has branded 'Rock of Ages' a ''complete disaster''.

The '30 Rock' actor - who played Dennis Dupree in the 2012 big screen adaptation of the hit Broadway musical - has hit out at the ''horrible movie'', which co-starred Tom Cruise and Russell Brand.

Speaking at the American Magazine Media Conference in New York earlier this week, he said: ''It was a complete disaster. A week in you go, 'Oh God, what have I done?' ''

The actor explained that he only agreed to be in the movie because he wanted to work with director Adam Shankman, who previously helmed the 2007 musical movie 'Hairspray'.

The Emmy Award-winning star also criticised Hollywood studios for only greenlighting big budget movies such as 'Spider-Man' and believes the lack of diversity has made movies less interesting than viewers' own lives.

He added: ''Now people's own lives are more interesting than what's in the theatres. They [studios] only want 'Spider-Man'.''

'Rock of Ages' proved to be a box office dud last year, despite starring A-list actor Tom Cruise in the lead role.

The film grossed a paltry $59 million worldwide based on a $75 million budget.