The former Ballon d'Or winner had appeared to be edging towards a return to Europe, with Besiktas particularly keen, but the ex-Barcelona star decided to remain in Belo Horizonte
The 33-year-old attacking midfielder looked set to leave the Copa Libertadores champions after allowing his contract to run down.
However, despite interest from Turkish outfit Besiktas, Ronaldinho signed a new deal with Atletico on Thursday, with his representative, and brother, Roberto Assis, insisting that leaving Belo Horizonte was never on the cards.
"It was invention of the journalists," he told Radio Itatiaia. "We had a meeting [Atletico Mineiro] and it was all resolved."
Prior to signing a contract extension, there had been speculation that Ronaldinho wanted one last crack at Europe.
Assis confirmed that an offer was made by Besiktas but denied any insinuations that Ronaldinho was ready to consider the deal, saying his brother retains a special affinity with the Atletico supporters.
"There is a fantastic relationship there," he enthused. "He's happy there.
"He met with a crowd that was extremely affectionate with him and his whole family. The player feels very comfortable."
Ronaldinho, who won the World Cup with Brazil in 2002, inspired Atletico to Copa Libertadores victory last year.