Belgian international defender Arthur Theate has joined Ligue 1 side Rennes from Italian outfit Bologna, the French club announced.
No financial details were revealed but French press reported the deal is worth around 20 million euros ($20.4 million).
Theate has signed a four-year contract.
He came through the youth ranks of Belgian clubs Genk and Standard Liege, before signing his first professional contract with Oostende.
The 22-year-old moved to Bologna on loan with an obligation to buy in 2021, playing 31 games for the Serie A club.
Rennes had been looking to fill the gap following the departure of Moroccan defender Nayef Aguerd for West Ham for nearly 35 million euros.