'The Hangover III' will begin production in September.

The third instalment in the comedy movie series - starring Bradley Cooper, Zach Galifianakis and Ed Helms - is planned for a May 2013 release, although a storyline is not yet known.

President of Warner Bros. Pictures Group Jeff Robinov revealed he was delighted to have director Todd Phillips back on board for the project.

He said in a statement: ''We are extremely pleased to have Todd Phillips and the guys back together again for another 'Hangover' and we look forward to collaborating with them on another great movie.''

Todd added: ''I'm so excited to embark on another 'Hangover' film with Bradley, Ed and Zach. We're going to surprise a lot of people with the final chapter we have planned.

''It will be a fitting conclusion to our three-part opera of Mayhem, despair and bad decisions.''

Craig Mazin and Todd will write the screenplay for the project.

Speaking about the project previously, 'Limitless' hunk Bradley claimed it would be unlikely to ''adhere to the structure'' of the previous two movies.

He said: ''We adhered to the formula in the second one, for those of you who've seen it, and the third one, which would close the whole, sort of, trilogy, which now it would be a trilogy - even though we thought we would never make a second one, let alone anybody see the first one.

''I think it will take place in Los Angeles and maybe not adhere to the structure. It might be different.''