Reports from Croatia claims the deal is close to being completed, but Spurs are still pushing for a bigger fee.
The 26-year-old has long been linked with a move away from White Hart Lane.
An anonymous source told Croatian website www.24sata.hr: “Everything has been resolved satisfactorily.
“Luka and Madrid agree on everything. Things are a bit more difficult with the position of Tottenham, but everything will be resolved, and quickly.”
Modric has also been linked with the likes of Chelsea, Manchester United and Paris St Germain.