The French side have already rejected one offer, in the region of £6 million, for the Czech international.
Rennes want to keep Cech until June, while Chelsea would like to sign him during this month's transfer window.
Chelsea are keen to sign the highly-rated shot-stopper and have re-enterted talks with Rennes to bring him to Stamford Bridge.
The 21-year-old is now hoping that both clubs can come to an agreement to allow him to move to West London.
"I have that proposition of Chelsea in my mind every day. I know that discussions between clubs are going on," said Cech.
"There will be a new meeting soon between people from both clubs and I hope that something good will come out. I really want to go to Chelsea."
Cech revealed he had talked with Rennes general manager Pierre Dreossi to explain his situation that he wants to take the chance to join Chelsea.
"I talked with Pierre Dreossi about this. He explained to me his position and the fact that he wants to keep me until the end of the season. Then, I explained my point of view," added Cech.
"Rennes have to understand that Chelsea is a big challenge for me. I won't let go of that chance.
"Chelsea want a new goalkeeper now and they won't wait until June to get me. They will probably take someone else if they don't find an agreement with Rennes.
"I am still optimistic because the offer of Chelsea is very important.
"My agent is in London," confirmed Cech. "I will be disappointed if the deal will not be done."
Rennes are believed to be considering replacements for Cech with Bastia's Nicolas Penneteau or Marseille's Vedran Runje among their targets.
