As first revealed by planetfootball.com, Sam Allardyce targeted the French international and invited him to undertake a trial with the Premiership leaders.
The 30-year-old will spend the entire season with his new club after l'OM agreed to the transfer last week.
"Bruno will be a great addition to the squad," Allardyce told the official Bolton website.
"He is an experienced European player who is looking to prove himself in The Premiership.
"He is also very tall and physically strong, and this will be of great benefit to us."
'Big Sam' has spent the past week running the rule over another Frenchman, Monaco's Nicolas Bonnal, and is deciding whether to pursue his interest in the forward.
Click here to read how we broke the story in England.
