Officials from the Italian club were flying in for further talks with Leeds last night.
Leeds' managing director, Bill Fotherby, said: 'There is some way to go yet, but we are hopeful of reaching agreement by tomorrow.'
The fee would beat Leeds' current record of pounds 2.7m, which they paid Sheffield United last summer for the striker Brian Deane.
But the fee is dwarfed by the pounds 5m asking price for Norwich's Chris Sutton, which is alarming the Professional Footballers' Association chief executive, Gordon Taylor. He fears the sale of the 21-year-old, who is being chased by Blackburn and Arsenal, could cause an escalation of transfer fees.
Taylor believes that higher fees may force smaller clubs to look overseas rather than buy home-grown talent.
Taylor said: 'Chris obviously has tremendous potential, but he isn't the finished product yet and you couldn't call him a world-class player or even an international star. It worries me we seem to be following the Italian lead when it comes to transfer fees.'
Taylor warned that following the Italian path could prove a dangerous step. 'If the fees for British players continue to go up like this, only the richest clubs will be able to compete and the other clubs will have to look abroad for cheaper options,' he said.
'The Sutton deal, if it goes through, will trigger a lot of others and Norwich could get three, four or five players with the money they get for him.
'If that money stays in the domestic game, we won't be concerned, but if it starts to drain away in Europe, we would be very worried.'
Meanwhile, the Wolverhampton Wanderers manager, Graham Taylor, has made his third major signing of the summer with the pounds 600,000 purchase of Millwall central defender Neil Emblen. The arrival of the 23-year-old former Sittingbourne player takes Taylor's summer spending to pounds 2.85m.
Taylor's other two signings this summer have been the wingers Tony Daley and Stephen Froggatt, from Aston Villa, for a combined pounds 2.25m.Reuse content