The purported move for the former Ajax Cape Town man is expected to be finalised within the next 24 hours, one of the agents involved in the negotiations, Bruno Satin, said.
“It is almost sorted. I’m sure they will get him. They have lifted their fee,” Satin told Times Live in Libreville.
“I reckon it could be done by the end of the day. They really want him,” he added.
The club has been following Dolly’s progress since the 2015 under-23 African Championship in Senegal.
Should the French club finally land their man after a contractual wrangle involving a R25 million buyout clause from Downs, Dolly will join Kermit Erasmus (Rennes) and Lebo Mothiba (Lille) as the only three South African-born players plying their trade in France.
Dolly joined Sundowns from Ajax Cape Town in 2014 and he was loaned back to the Mother City for a season before arriving at the start of last season.
He went on to make an immediate impact, and alongside Leonardo Castro and Khama Billiat, he took his game to another level.
He also helped the Tshwane giants win the PSL and Caf Champions League titles, before representing the club at the 2016 Fifa Club World Cup in Japan.