Hollywood pays tribute to late Godfather actor
Caan played Sonny Corleone in Coppola's classic 1972 gangster movie.
Pacino, who starred as Michael Corleone, described him as a "great actor" and a "dear friend".
Ford Coppola said Caan's work "will never be forgotten".
In a statement provided to the PA news agency, the director said:
"Jimmy was someone who stretched through
my life longer and closer than any motion picture figure I've ever known."
"From those earlier times working together on [1969 film] The Rain People
and throughout all the milestones of my life, his films and the many great
roles he played will never be forgotten."