Santos said it could not match the offers made for the 31-year-old striker, especially from international clubs.
Robinho said that "unfortunately it won't be possible to renew the contract, but Santos will always remain in my heart."
"I want to thank club directors for trying hard to make it possible for me to stay so everybody could be happy," he said. "I'm upset because this is like my family, but life goes on. Santos will remain big and I will try to be happy doing what I like the most, which is playing football."
Brazilian media reported that Robinho has reached a deal to join big-spending Chinese Super League club Guangzhou Evergrande for 12 million euros ($13.3 million) per year.
However the Chinese club denied any deal had been reached.
In a telephone interview from Guangzhou, club spokesman Wang Yunhao said there was no contract with Robinho.
"There is no such thing," Wang told The Associated Press on Wednesday.
Santos president Modesto Roma Jr. said Robinho "will continue his career with another club and we wish success to our eternal idol."
The reported move comes a day after the club announced that Brazil midfielder Paulinho was leaving Tottenham to join Guangzhou Evergrande for 14 million euros ($15.5 million). Scolari, Brazil's former 2002 World Cup-winning coach, was also hired this month to lead the team.
Since being purchased by the Chinese real-estate group Evergrande in 2010, the club has gone on a massive spending spree to build a championship-caliber team.
It's had a trio of World Cup-winning coaches, with former Italian captain Fabio Cannavaro and former Italian coach Marcello Lippi preceding Scolari, as well as high-priced players like Argentinian Dario Conca and Brazil international Ricardo Goulart, who signed this year for a CSL-record $16.2 million (‚¬15 million).
In 2013, Guangzhou became the first Chinese team to win the Asian Champions League.
Robinho returned to Brazilian football last year on a loan from AC Milan. He has played three different stints with Santos, scoring 111 goals in 253 matches.
He also played for Brazil in the 2006 and 2010 World Cups and this month's Copa America tournament, where Brazil was eliminated by Paraguay in the quarterfinals.
Associated Press writers Chris Bodeen and Justin Bergman in China contributed to this report.