Mancini has been Lazio's coach for the last two seasons

The appointment of Mancini, 39, who is leaving Lazio, came hours after Alberto Zaccheroni resigned as Inter's coach.

Mancini had been Lazio's coach for two seasons. He started his coaching career at the Rome club as aide to Sven-Goran Eriksson, now England's coach.

The former Sampdoria striker is Inter's 11th coach since oil industrialist Massimo Moratti took over the team a decade ago.

Zaccheroni led Inter to fourth spot in Serie A last season and it ensured that they qualified for a spot in the Champions League.

But his time at Inter has been clouded by a number of disagreements with star striker Christian Vieri - and this may have influenced his decision to resign.

Inter also crashed out of the Champions League at the group stage last season.

Vieri has had a troubled campaign and has been linked with moves to Real Madrid and Juventus this summer.

But Inter are determined to hold on to their prize asset and former president Massimo Moratti appeared to publicly lose faith in Zaccheroni's abilities.

Zaccheroni took over at the the San Siro last October following the sacking of Hector Cuper.

He had already proved his Serie A credentials by leading AC Milan to the Scudetto in 1999.