Manchester City have agreed a 40m euros (£33.6m) deal with Lens for central defender Abdukodir Khusanov.
Sources with knowledge of the deal say there are additional bonus payments attached to the sale, with the player due to undergo a medical before the transfer is officially confirmed.
City manager Pep Guardiola has been determined to strengthen his squad after a difficult couple of months which has seen the defending Premier League champions slip to sixth in the table - and 12 points behind leaders Liverpool.
The club are also in negotiations with Brazilian side Palmeiras for teenage defender Vitor Reis, although the club's president has been quoted as saying reports they are keen to cash in on the 18-year-old are "not correct".
In addition, City are keen on Egypt forward Omar Marmoush following the 25-year-old's impressive displays for Eintracht Frankfurt this season.
Khusanov will become the first Uzbekistan player to join a Premier League club once his move is completed. He will also be City's first significant January signing since the arrival of Aymeric Laporte in 2018.
It underlines Guardiola's determination to reverse City's fortunes and address a chronic injury situation that has left him without a succession of defenders during the first half of the campaign.
Ruben Dias has not featured since the derby defeat by Manchester United on 15 December and has been ruled out of Saturday's FA Cup third-round tie with League Two side Salford City.
England's John Stones will also miss the game, while Nathan Ake has twice been ruled out for extended periods because of injury already this season.
Lens only paid 100,000 euros (£84,000) for Khusanov from Belarusian club Energetik-BGU 18 months ago.
However, he has developed rapidly and made 13 appearances in Ligue 1 so far this season and has 18 caps for Uzbekistan.
Khusanov scored his first goal for the club on his most recent appearance, a French Cup tie with Paris St-Germain on 22 December.
City have also been handed welcome news with the return to training of Oscar Bobb after the 21-year-old Norwegian's five-month absence with a fractured leg.