Zouma spent last season on loan at Stoke City and faced an uncertain future under new boss Maurizio Sarri, with Antonio Rudiger, Andreas Christensen, Cesar Azpilicueta, Gary Cahill and David Luiz providing competition for places in central defence at Stamford Bridge.
Reports emerged yesterday suggesting that both Manchester United and Everton were interested in the 23-year-old, with United thought to be keen on a permanent deal.
However, Chelsea are understood to prefer a loan, and L'Equipe now claims that they have agreed terms with the Toffees over a season-long deal for the France international.
Personal terms are still yet to be agreed, though, with Everton attempting to push through a deal before the 5pm deadline this afternoon.
Any move for Zouma could see Everton end their interest in Barcelona defender Yerry Mina, who has also been linked with United.