"The midfielder has agreed to a six-month deal, with an option of a further 12 months to follow," City said in a statement on their official website.

"Vieira's signing from Inter Milan was completed on Friday morning. He will take the squad number 24."

The 33-year-old becomes the first signing of City's new manager Roberto Mancini, who took over at the club last month following the abrupt sacking of Mark Hughes.

He left Italian champions Inter in a bid to play regular first-team football and break into France's squad for the World Cup finals in South Africa in June.

Vieira's deal with the Nerazzurri was due to expire at the end of the season.

The former Arsenal men believes City, who lie fifth in the table, are capable of causing an upset and winning the Premier League title.

"We should not be afraid to say that we are good enough to win the league because we are and as a team we should believe we can do it," he told the club's official website.

"At Arsenal one year we won the title from 15 points behind at Christmas. Everything is possible."