The 24-year-old Romanian joins the FA Cup holders as cover for England international Joe Hart following the departure of Shay Given to City's top-flight rivals Aston Villa.
Pantilimon, signed for an undisclosed fee, made his Romania debut in 2008 and played against City twice in the Europa League last season, conceding three times.
He is now expected to leapfrog Stuart Taylor and Gunnar Nielsen in City's goalkeeping pecking order to be Hart's deputy.
Given joined Villa earlier in pre-season after losing out to Hart in the battle to be City's first-choice keeper.
Pantilimon is manager Roberto Mancini's fourth pre-season signing, following left-back Gael Clichy from Arsenal, defender Stefan Savic from Partizan Belgrade and Argentina star Sergio Aguero, who arrived at Eastlands from Atletico Madrid in a deal worth around ?£38 million.
Italian boss Mancini said he hopd to bring in "another two or three players" before the transfer window deadline at the end of the month.
City play local rivals Manchester United in the Community Shield, the traditional curtain-riser to the English season between the FA Cup holders and the league champions, at London's Wembley Stadium on Sunday.
Source: AFP
Source: AFP