Juve clinched Ronaldo's signing for €112m this week.
Marotta said: "It was great team work. Yes, we are happy, very happy. And the real protagonists are the player and the shareholders of Juve.
"It was Cristiano Ronaldo who was the first to believe in this operation, the first to launch it. He chose Juve. And when we understood that we could seize this opportunity, the shareholders of the club agreed to support us.
"I insist, it was great team work.
"The beginning of the operation? When we started talking to (Joao) Cancelo, who has the same agent as Ronaldo, namely Jorge Mendes. We want to express our maximum happiness and satisfaction for Operation Cristiano and his choice to join Juve. Cristiano is very happy to be able to play for one of the most important clubs in the world, he's chosen where he will live."