The Wales international has been frozen out by Real manager Zinedine Zidane and said earlier this month that he was open to returning to the Premier League.
It has been reported that Spurs and Manchester United are interested in signing Bale but Jose Mourinho appears to be leading the race to land the 31-year-old.
“It’s close but not done,” Bale’s agent Jonathan Barnett told AFP. “It’s a complicated deal.”
Bale has two years left on a contract that pays him a reported salary of about £600,000 ($775,000) a week at Real.
It has been reported the Spanish club would be willing to pay some of that salary to finally move on from their troubled relationship with the forward.
Bale left Tottenham for Real in 2013 for a then world-record fee of £85 million.