The NYC "Olive Oil Business" was important enough to Michael that he held onto it after moving the Family to Nevada--first through Clemenza, then through Pentangeli, acting as caporegimes. The Rosato brothers wanted it because they were greedy for the whole enchilada, not just the three territories in the Bronx that Clemenza allegedly promised them before he died. Roth supported the Rosatos killing Pentangeli because, if his plan to have Michael killed in Havana succeeded and the Rosatos took over the NYC operation, Michael's successors would be deprived of that muscle they could have used in the event of a war.

But, by the end of II, all we know about the Olive Oil Business in NYC is that Pentangeli flipped, and Roth and the Rosatos were "on the run." The next we hear about the Olive Oil Business is at Michael's party in III, when he says to Vincent: "Mr. Joe Zasa now owns what used to be the Corleone family business, in New York." Zasa replies: "I earned it through my talent."

Zasa looked to be about 40 in 1979, when III opens--too young to have taken over after Frankie flipped. What do you think happened to the Olive Oil Business after Frankie flipped?