The former AC Milan midfielder was presented to the local media on Wednesday at the Nou Camp.
Laporta said, “I welcome Kessie, his family and his agent.
"They have worked well with (directors) Mateu (Alemany) and Jordi (Cruyff) to make this signing possible. The player showed his will to reach an agreement. We're satisfied because we have fulfilled one of the requests from the coach.
"We're matching his expectations, that's our objective in this transfer market. Franck is one of the midfielders who we missed most, who can arrive in the box and who knows how to protect the defence."