Al Pacino was offered $5 million to reprise his role as Michael. But Pacino wanted $7 million plus a percentage of the gross. Francis Ford Coppola refused. He threatened to rewrite the script by starting the story with Michael's funeral sequence instead of the film's introduction. Pacino agreed to the $5 million offer.
Al Pacino stated that he did not agree with the portrayal of Michael in the film. He didn't believe that Michael would ever feel regret or remorse for his actions, especially the murder of his brother.
Robert Duvall turned down the $1 million that the studio had offered to re-create his role of Tom Hagen. Duvall did not feel that his proposed salary was commensurate with what Al Pacino and Diane Keaton were getting ($5 million and $1.5 million, respectively). The character was subsequently written out. Duvall later defended his position, explaining that making money was the only reason to produce another Godfather movie after so many years.
Francis Ford Coppola once admitted that he was still unhappy over the final result because of lack of time to write the script. According to him, he had wanted $6 million for the writer, producer, and director fee and 6 months to write the script. Instead, the studio gave him only $1 million in fees and only 6 weeks to work on the script (in order to meet the Christmas 1990 release date). He also regretted that the character of Tom Hagen had to be written out of the script because the studio refused to meet Robert Duvall's financial demands. According to Coppola, with Hagen gone, an essential character and counterpart for Michael Corleone was missing from the movie.
Sofia Coppola had to redub about twenty percent of her original dialogue for the final cut after a disastrous early screening for the New York press on December 12, 1990, where many of the critics acrimoniously singled out her performance. According to an interview in Entertainment Weekly the following month, she said her greatest vocal challenges for the role were eschewing her "Valley Girl" accent, and correctly pronouncing the name "Corleone".
Willie Brown: The former Mayor of San Francisco (1996-2004) appears as the black man who manages to have a word with Michael in the party sequence. He appeared as a personal invitation by Francis Ford Coppola. He is the only black person to appear in a speaking role in all of the three Godfather films combined.
Sonny Grosso: The man who rudely interrupts the New York City stockholders press conference. A detective and former partner of Eddie Egan (fictionalized in The French Connection (1971) as "Popeye Doyle") he was the inspiration for Doyle's partner Sonny.