The 28-year-old has signed a four-year contract after free-spending City agreed a fee of a reported £15million with the Gunners.

Toure joined Arsenal as a largely unknown 20-year-old from ASEC Mimosas in 2002, but now moves to City as an accomplished defender with Champions League experience and 70 caps for Ivory Coast.

"It is always difficult to leave a place where you have spent the last eight years and had good times but I felt the time was right for a new challenge and I am still at an age, 28, where I feel I am at my peak and will play my best football," Toure told City's website.

"For me it was time to move but only for the right club and I feel that Manchester City is that club. The ambition here is clear to see and is big. Everyone knows this club is moving and that is really, really important.

"I still want to achieve things and I feel as though I can bring something to City and that is what I will be striving to do. It is not just about quality on the pitch it is about blending as a team and with my experience I think I can help City do just that."

City hope that Toure is the latest piece in an expensive jigsaw that can catapult them into contention for a Champions League place.

"I am delighted to welcome Kolo to Manchester City," manager Mark Hughes said.

"It is no secret that we have been looking to strengthen our defence, and in Kolo I feel we have recruited a world-class player. He brings a wealth of Premier League experience."

Toure will be unveiled to the media tomorrow alongside a delighted Hughes, who added: "Kolo has been a central figure in a very strong Arsenal team for many years.

"I have been an admirer of him for a long time. He is strong, quick, reads the game well and will be an influential figure in the dressing room."

Hughes turned to Toure after his efforts to bring in John Terry were rebuffed first by Chelsea, then by the player himself.

Toure's arrival is City's sixth signing of the summer. His former Arsenal team-mate Emmanuel Adebayor has already checked in along with Carlos Tevez, Roque Santa Cruz, Gareth Barry and back-up goalkeeper Stuart Taylor.

However it is understood that City are still keen on Everton's Joleon Lescott.

Toure struggled to find his best form last season after the African Nations Cup.

He was shunted out to right-back when Bacary Sagna got injured and went on to make 26 starts in the league.

Toure, however, was recognised as Arsenal's most established centre-back and the only remaining regular from the 'Invincibles' side of 2003-04.

A utility player when he arrived in 2002, the Ivorian quickly blossomed into an top-class defender.

He won over manager Arsene Wenger with his strength, pace and his ability to break up the play.