James Michael Tyler, who played Gunther in the series, told the News of the World that Friends: The Movie is "definitely on".
"I still keep in touch with a lot of the cast and they say that they are really keen," he added.
The programme's creators David Crane and Marta Kauffmann have reportedly agreed to write and produce the film, which will be shown in cinemas in 2011.
"The cast haven't set the world alight since the show finished," a source said. "But this film could relight some of their careers in a big way.
"Everyone knew the story had to be right and well-written. Getting the creators on board was a massive step forward for the production.
"The show did lose its shine in the last few seasons, but with the actors all in their forties it would be a real interest to see how their characters have developed."
Tyler added: "The one thing I can tell you is I am definitely on board to do the film. I really loved my time on the show and I am looking forward to meeting up with the old gang again.
"I just hope we can do justice to the show in a film."
Members of the cast have previously denied rumours of a Friends film.