Tanja Munzig, of the Sea Life Aquarium in the western German city of Oberhausen, said they had received offers for Paul but he was not for sale.
"There are a lot of offers for Paul from betting offices and other areas. One thing is clear: Paul is staying with us," she said.
She added he would now "step back from the official oracle business".
"He won't give any more oracle predictions - either in football, or in politics, lifestyle or economy. Paul will get back to his former job, namely making children laugh."
Paul made his uncanny predictions for each game by choosing a mussel from one of two jars bearing the flags of World Cup opponents.
The two-year-old cephalopod quickly became a worldwide celebrity.
Seemingly unimpressed with his star status, Paul at first ignored the golden trophy - adorned with three mussels - placed in his tank.
But after several minutes he finally picked off a mussel and devoured it in front of TV cameras.