Many have suggested the hedge fund would buy and flip Inter for a quick profit, but Marotta insists they're committed to a long-term project.
He told Sky Italia: "Oaktree arrived on tiptoe, silently, but in a concrete and participatory way in the club. The relationship is positive and daily, all aimed at ensuring the search for economic and financial sustainability.
"This sustainability occurs through agreed guidelines, that is, composing a squad that responds to economic limits in terms of labor costs, at an average age that can guarantee the fact of investing in young people who represent an asset, an element that contributes to providing sustainability.
"In the next season we will guarantee maximum competitiveness through players who are younger than those of today, but who also represent quality, professionalism and heritage."
Asked if he will be staying long-term, Marotta also said: "Yes, I'm happy at Inter so I hope to produce results, contribute to achieving them."