How come Anthony Corleone in II wasn't reprised?

The kid in The Godfather, Part II was played by James Gounaris - the older brother of the kid who played Anthony in Part I - how come he wasn't hired on to play the adult Anthony in Part III?

Is it because they wanted someone who could sing opera?? Ugh, what a storyline...

For all the heat Sofia Coppola and George Hamilton have taken regarding their acting in GF III, I think the guy who was cast for Anthony did a perfectly horrible job. They didnt need someone who could sing.. it could have been lip synched. For my taste this actor was way too light in the loafers (no offense to my gay friends) to be Michael Corleone's son. When Kay says to Michael that Anthony is just like he was as a young man, it simply doesn't sell. Anthony is this wimpmy self-righteous little wuss, hiding behind his mother's skirts to stand up to his father. When young Michael and Vito went at it, you didn't see Michael asking Mama Corleone to intervene for him.

But don't forget sicilian values are sexist towards woman. Many sicilians in the gf books and movies bielieve that men are the superior race. And the sicilian woman go along with it like mama. But Kay is a American woman whose society is a lot less sexist.