The 26-year-old has declared that he would like to leave Anfield and has long been linked with a move to join up with former boss Rafael Benitez at Inter Milan.
“I sent an offer to Liverpool by fax on Tuesday and I am waiting for a reply from them,” Branca said in The Sun.
“We’re not speaking to the player at the moment because we want to do this in the right way and make sure that Liverpool are happy.
“Everybody knows that Mascherano would like to change team and to change country. He also has a good relationship with our manager Rafa Benitez.
“We’ve made a very good offer, around the amount they are asking for. We have a strong team here, the best in Europe, but we would like to add one or two players to make us even stronger.”