Actor Dan Aykroyd has expressed his sadness after learning of the death of his Ghostbusters co-star Harold Ramis.
Ramis died on Monday from complications of a rare blood disease.
Aykroyd and Ramis starred alongside Bill Murray and Sigourney Weaver in the supernatural comedy Ghostbusters, released in 1984.
The film about three eccentric parapsychologists who get into the ghost catching business was a big hit, grossing more than $US291 million ($A323.08 million) worldwide. It spawned a sequel in 1989, two animated television series and several video games.
Aykroyd has paid tribute to his friend and collaborator via a statement issued to The Hollywood Reporter reads.
The statement reads: "(I am) deeply saddened to hear of the passing of my brilliant, gifted, funny friend, co-writer/performer and teacher Harold Ramis. May he now get the answers he was always seeking."
Aykroyd had been working with Ramis for some time to bring Ghostbusters 3 to the big screen, but it is not yet known how his death will affect the project.
Meanwhile, comedian Steve Martin has commented on Ramis' passing via Twitter, writing, "So sorry to hear about the death of Harold Ramis, a comedy master. Ghostbusters, Groundhog Day, and more."
Actress Julianne Moore tweeted, "Very sad to hear that we lost Harold Ramis. Exceptionally talented, exceptionally kind."
His Year One co-star Christopher Mintz-Plasse has also expressed his thoughts online, tweeting, "SO lucky I got to work with Harold Ramis, even if just for a couple weeks. The nicest, most talented gentleman. God damnit. RIP."
Year One, a prehistoric comedy released in 2009, was Ramis' final movie as both an actor and director.
