Widespread media reports in Britain suggest City will part company with Mancini, who has been in charge since 2009 and who won the Premier League title last season.
City have fuelled the intense speculation about Mancini's future by remaining silent over the rumours, but Pellegrini has moved to distance himself from reports suggesting he was on the verge of replacing the Italian.
"I categorically deny that I am the new Manchester City coach, nothing has been signed and no agreement reached," he said on Malaga's website following their 0-0 draw with Sevilla.
"I've been fortunate enough, and very proud, that every year the big Clubs are interested in me.
"I have an agreement with Malaga not to talk to anyone and nothing has been agreed with any other outfit.
"I hope the future of this Club will become somewhat clearer in the next few days."
Manchester City, beaten 1-0 by Wigan Athletic in Saturday's FA Cup final, have two Premier League games remaining this season starting with relegated Reading on Tuesday.
They require one point to guarantee runners-up spot from runaway champions Manchester United.
However, City's failure to win a trophy this season, and their dismal flop in the Champions League for the second successive year, has put him under the spotlight.
Mancini has cut a disgruntled figure as speculation about his job mounted and appeared to criticise the club's owners after the Wigan defeat.
"I don't know why the club didn't stop this, because I didn't think it was correct," he said. "I don't think that it's true."
