Manchester City have apologised to Manchester United and Sir Alex Ferguson for any offence that may have been caused by Carlos Tevez holding up a sign reading "RIP Fergie".
The incident occurred during the Citizens' title parade through the city on Monday and caused an uproar from United fans.
It is believed that the banner was a response to a statement that Ferguson made three years ago, when he claimed that City would not topple the Red Devils "in his lifetime".
City chiefs have moved quickly to douse the flames by apologising, calling the Argentine's actions a "significant error in judgement".
"The creation of the tasteless material is in itself reprehensible and in accepting and brandishing it, Carlos has made a significant error of judgement," said a Manchester City spokesperson.
"The club wishes to express its sincerest apologies to Sir Alex Ferguson and Manchester United Football Club for any offence or distress caused."
The 28-year-old also personally apologised for his lapse in judgement.
"I got carried away in the excitement of the moment and I certainly didn't mean any disrespect to Sir Alex Ferguson, who I admire as a man and a manager," said Tevez.
Tevez created a storm in 2009 by moving from Old Trafford to the Etihad Stadium.