Nantes chief Waldemar Kita says a deal to sell Aston Villa and Liverpool target Jordan Veretout to a Premier League club is "basically agreed".
Charlton have made their seventh signing of the summer by landing defender Naby Sarr from Sporting Lisbon.
The 34-year-old former Bayer Leverkusen and Bayern Munich player passed a medical in Turin earlier on Wednesday before putting pen to paper.
In his time at Inter, Lucio won one Scudetto, two Coppa Italia, one Super Coppa, the Champions League and the Club World Cup.
He lifted the World Cup with Brazil in 2002 and has now been given the chance to remain in Serie A after switching to Juventus.
A statement on the club's official website read: "Lucio has completed a move to Juventus.
"The Brazilian defender joins the Bianconeri on a free transfer and has signed a two-year contract, keeping him with the club until 30 June 2014."
Lucio added: "I am happy with this new experience, it is a new chapter of my life. Juventus have always been a strong side and I hope to help the team.
"I'm ready to do my best for the team and want to use my strength and experience to always give Juve the chance to be in first place."