The German club are asking for in excess of £10 million (€14.6m) for the 25-year-old, who has scored 20 goals this season to fire Bayer to the brink of UEFA Cup qualification.
Reports in Germany suggest Manchester United could also enter the bidding for Berbatov due to the uncertainty over the future of Ruud van Nistelrooy.
Bayer’s director of football Rudi Voller said: “Tottenham have spoken to us again and are now prepared to match our asking price. The decision lies with Dimitar.
“It is understandable that he wants to try something new after six years in Leverkusen, but it will hurt us to lose such a great player.”
Meanwhile, Tottenham have revealed initial tests by the Health Protection Agency into the suspected food poisoning outbreak are inconclusive, despite the discovery of a virus in one of the affected players.
Ten Spurs players were struck down with suspected food poisoning on the morning of their final game of the season against West Ham after eating lasagne at the team’s Canary Wharf hotel.
Although Spurs tried to get the Premier League to delay the start of the game, the club fulfilled the fixture even though players were vomiting in the dressing room right up until kick-off.
Spurs lost the match 2-1, wrecking their hopes of playing in the Champions League next season as Arsenal leapfrogged them into fourth place in the Premiership.
The initial report from the Health Protection Agency and Tower Hamlets Environmental Health showed one player was suffering from a virus that could have been responsible for the outbreak of illness among other players. But the report also revealed that the virus was not present in another player who was suffering from the same symptoms.
Spurs are awaiting the results of further tests before they hope to be able to pinpoint the cause of the illness.
Tottenham’s head of medical services Dr Charlotte Cowie said: “The information received so far is inconclusive, but more importantly, the results shown as yet are inconsistent.
“Despite there being the presence of a virus in one sample, it is not present in another sample from an equally affected individual. Therefore, it would be incorrect to make any assumptions at this stage as to the origin or timing of this and, if anything, it serves to sustain our level of uncertainty.
“I should also like to stress at this point we are awaiting the results of further tests. It really is far too premature to draw any conclusions from such an initial set of results.”
Michael Dawson, Edgar Davids, Michael Carrick and Robbie Keane were struck down with the illness but all four played in the game. The Premier League has rejected Tottenham’s request to replay the match.