Malky Mackay has confirmed that Cardiff and Toulouse have come to an agreement over the transfer of Etienne Capoue.
However a deal is not concluded as the newly-promoted Premier League side have still to talk to the player and his advisors.
Cardiff are believed to have bid around £9 million for the France international striker, who is also interesting Atletico Madrid.
"Ourselves and Toulouse have come to an agreement," Mackay said.
"We've got to then have the conversation with Etienne and his advisors, they've been very professional in terms of what they're talking about as well.
"We've been in constant dialogue with them in the last week and Toulouse have been excellent to deal with.
"It's pretty delicate at the moment. We're in discussions and negotiations but it's something that's ongoing."
Meanwhile, Cardiff are also hopeful of signing Brentford goalkeeper Simon Moore.
The club have only recruited Denmark striker Andreas Cornelius and Derby County full-back John Brayford so far this summer but Moore, 23, is seen as competition for the club’s first-choice goalkeeper David Marshall.
"It'll be paperwork first thing Monday morning, that's the only thing holding that one up," Mackay said.
"I'm glad to get that one in, he's someone we've tracked for a year and he's had a successful year for Brentford.
"He's one that I think is a real prospect. For the future of the club, I've got three really good goalkeepers now; Simon comes in and I think he can kick on again.
"My thanks to Brentford for the way they went about their business, they were very professional and it was done very quickly."