West Ham manager Sam Allardyce has confirmed he is keen to retain the services of on-loan striker Andy Carroll.
Goalkeeper Colin Doyle has penned a new two-year contract at Birmingham.
The 6ft 3in midfielder moves to Molineux with a view to a permanent deal having completed a medical on Friday before joining his new team-mates for training over the weekend.
"I am delighted we have managed to sign Tongo who will bring some more quality to the squad," boss Stale Solbakken told Wolves' official website.
"He also has good experience for a young player and made 26 appearances last season for a top six club in France.
"He is a box-to-box player who can operate in that central role defensively and offensively and as well as being physically strong he is also good in possession.
"We'll have another look at him on Tuesday but there is a chance he will be involved in the game against Shrewsbury."