"I am delighted to be able to give all of my efforts to Manchester City for a further five years. The opportunity that exists to build on our recent success is enormous." Mancini said on Monday
The Manchester city was in touch with Mancini , and the negotiations were going around since Mid-May, resulting in rumors that why isn't Mancini making a deal, until last night when  he confirmed his appointment.
Mancini told the club's website. "I am very much looking forward to the challenges and excitement ahead." He added: ‘We have laid the foundations and now we want to win more. If we do that then we can be one of the most successful clubs for a long time to come and that is the aim.’
Confirming the length of the new deal, a statement from the club said: "Manchester City Football club are pleased to proclaim that a new agreement has been signed with manager Roberto Mancini. The contract, which runs until the summer of 2017, follows the club's most successful season in more than four decades, which concluded in the most dramatic of circumstances in the team's thrilling 3-2 win over Queens Park Rangers in May this year [that won the Premier League title]. Agreement was reached after, in line with club policy, discussions began as the season closed."