It had been speculated that their move for the Italian had broken down, but Leonardi is confident of completing a deal for the 30-year-old.
"There's not much to talk about, the operation has started and we are quite confident," he told FcInternews. "But as is normal in these situations you have to put together all the components. Certainly there is a willingness on the part of everyone to arrive at the conclusion.
"I am not aware that Genoa might disturb the deal; we with Inter, from a corporate standpoint, have reached an agreement on everything and I do not think you want to sell the same player twice."
"The deal is quite advanced. We're working, we need calm. But there is a lot of confidence even though we have not yet reached an agreement, depends on many factors."
Cassano had also been linked with a move to Genoa.