Berbatov has been top of Fergie's wanted list all year and now he has turned his interest into a hard cash bid.
United are convinced they can lure the Bulgarian to Old Trafford with the promise of Champions League football and an £80,000- a-week pay packet.
Emil Dantchev, Berbatov's agent, said: "I cannot make any comment until there is official confirmation from Tottenham or United."