According to football411.com website, the People's Team, who were relegated from the Premier Soccer League at the end of last term, had designs on an immediate return to the top flight.
But they find themselves in ninth place with just three wins from their opening 11 games, and some 11 points adrift of league leaders Black Aces.
A brief statement on the club's official website reads: "We hereby wish to announce that Santos FC and Mart Nooij have amicably parted ways with immediate effect.
"We wish to thank Mart Nooij for his services and wish him all the best in his future endeavours."