Italian news agency AGI stated Thursday that the eight-time defending Serie A champions had reached an agreement with the decorated manager on a four-year contract worth €24 million a season.
The report added that plans to unveil Guardiola as the new Juventus manager have already been scheduled for June 14.
However, Alberto Galassi, a lawyer for City who also sits on the club's board, refuted the claim.
"I want to clarify what has been reported in the last few days and confirm what Guardiola said last week during the press conference," Galassi told Sky. "He wants to stay at Manchester City."
Sources close to Guardiola issued the same denial to reliable Goal correspondent Sam Lee.
"This rumor is unfounded," Galassi added. "It is unbelievable that the media pursue these kind of rumors. This is ridiculous. Guardiola wants to stay."
The mere mention of Guardiola's move triggered movement on the stock market, with shares in Juventus rising more than 3 percent on Thursday, according to Reuters.
Juventus are looking for a new manager after agreeing to part ways with Massimiliano Allegri, who won five consecutive Serie A titles during his time in charge of the Bianconeri.