**Standard Sport** understands that Liverpool will pay a guaranteed £55m, with a further £5m in add-ons. Jacquet will remain at Rennes for the remainder of the current Ligue 1 season, before moving to Anfield in the summer.
Chelsea are long-time admirers of Jacquet, who is considered one the most promising youngsters in Europe.
Talks between Rennes and the Blues began earlier in January, but a fee was never agreed as Rennes pushed for a club-record sale which would eclipse the €60m Manchester City paid for Jeremy Doku in 2023.
Chelsea were unwilling to match that asking price, but Liverpool have obliged after launching a late bid for the 20-year-old.
Personal terms will now be discussed, which are expected to be a formality.
Jacquet would likely replace Ibrahima Konate at Liverpool, with the centre-back's future at the club still uncertain as he enters the final months of his contract with little expectation of an extension being signed.
Liverpool have been looking for a new centre-back. They missed out on Marc Guehi, who joined Manchester City in a cut-price deal earlier this month, and briefly explored a loan move for Lutsharel Geertruida after talks with Sunderland.
Aaron Anselmino, who recently saw his loan move with Borussia Dortmund end early, will replace Sarr at the Ligue 1 side.