The 24-year-old joins City as back-up to first-choice keeper Joe Hart after signing from FC Timisoara on loan.
On his way: Costel Pantilimon (left) keeps out Man City's David Silva when playing for FC Timisoara in August 2010
Pantilimon, 24, impressed for FC Timisoara in last season's Europa League play-off against City and Mancini's side moved quickly to sign the stopper after the departure of Shay Given to Aston Villa.
City's new reserve has 13 caps for Romania, is highly-rated across Europe and has previously been linked with Inter Milan and West Brom this summer.
FC Timisoara, who finished second in the Romanian top flight this year, were relegated due to accumulated debts.
Romania's No 1: Pantilimon is highly rated across Europe
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