Dembele is out of contract at Barcelona next summer and is an attractive prospect for a host of clubs, with newly rich Newcastle claimed to have put a big offer on his table.
Barcelona are desperate to lock the attacker down on a fresh contract and avoid losing him, but Laporta admits the process is taking too long.
The Camp Nou supremo admits that Dembele is important for Barcelona and they want to keep hold of him; it has been suggested Barcelona have put a deadline on him accepting their latest offer.
Laporta told Spanish radio station COPE that the renewal is “a slower process than desired by us.”
He added: “For us, he is very important.
“He can be a key player if we can continue with him.”
It is unclear whether Dembele will agree to sign on the dotted line of a new contract at Barcelona or be tempted elsewhere on a big money contract.
Injury has limited Dembele’s ability to make an impact at the Camp Nou since he arrived and he has been restricted to just 73 minutes of football so far this season, across La Liga and the Champions League.