Manchester City have agreed a deal to sign Serbian left-back Aleksandar Kolarov from Lazio.

M.E.N. Sport understands that Roberto Mancini is about to secure his fourth signing of the summer - although the Italian club say any talk of a completed deal is premature.

Kolarov, 24, who can also play on the left-hand side of midfield, featured in Serbia’s first two games at the World Cup in South Africa.

He looked set to join Real Madrid last month but Lazio knocked back a £12m bid, insisting they wanted £19m.

However, it is understood a compromise on that figure has been reached a deal for around £16m has been agreed.

Mancini has been keen to sign a left-back to provide competition for Wayne Bridge, and has made no secret of his admiration for Kolarov, who he came up against when boss of Inter Milan. The deal will represent a profit for Lazio, who bought Kolarov from OFK Belgrade for £670,000 in 2007.

Lazio, however, insist they have yet to receive a written offer from the Blues.

Lazio president Claudio Lotito said: "Right now Aleksandar is a Lazio player and there is no agreement with Manchester City because I have not received a written offer."

The Italian media claim the two clubs cannot agree on a transfer fee with Lazio having placed a 22.5million euro price tag on the player and City willing to offer a reported 18million euros.

"Until an offer arrives we cannot discuss if there is a disagreement between the two parties (Lazio and Manchester City)," added Lotito.

Kolarov is under contract with the Serie A outfit until June 2011 but the Serbia international, who is currently on holiday, could leave the Rome side in the next 24 hours, according to Lazio coach Edy Reja.

Reja said: "His (Kolarov's) transfer will happen soon.

"We are closely monitoring what is happening."

What do you think? Have your say.