Officials from Paris St-Germain and Barcelona met in Paris on Tuesday to discuss a possible deal for Neymar to return to the Spanish champions.
According to BBC Radio 5 Live’s Guillem Balague, both clubs say the talks were “positive” but there is “still lots of work to do”.
Brazil forward Neymar, 27, joined PSG from Barcelona in 2017 for a world record fee of 222m euros (£200m).
Barca are offering 170m euros (£153m) for his return to the Nou Camp.
They might also offer players as negotiations continue, with Neymar said to be pushing for the deal to go through.
His entourage are said to be “optimistic”.