Peixe are keen to bring the forward back to his homeland, but admit that it will be difficult to strike a deal due to financial differences
The 28-year-old is believed to be keen on a move back to his former club, with Peixe star Neymar also calling for the Rossoneri star to agree a deal to join him back in Brazil.
"Robinho wants to return to Brazil and for him that means returning to Santos," Ribeiro told TV O Povo de Fortaleza.
"We have presented a written offer, though there is a difference between what the player and the club are asking for."
Robinho made over 100 appearances for Santos before moving to Real Madrid in 2005, but despite the player`s love for the club, the president was quick to concede that negotiations are likely to be tough.
"It can be circumvented, but it is not a simple task. It is a battle that must have results by the end of this week."