Thatcher had been linked with a move to Portsmouth

The Blues beat Portsmouth to secure the services of the Welsh international on a three-year deal.

"I am really looking forward to it now. Manchester City is a massive club and there was no saying no," Thatcher told the club's official website.

"Now I just want to get on with it, do my best, and hold down a first team place."

He added: "Until I signed for Leicester last year I had played all my football in London but it has not been a problem for me moving north.

"I played in the new stadium last year in the League game with Leicester and the City of Manchester Stadium is a fantastic place to play football."

Meanwhile Manchester City manager Kevin Keegan has also brought in Belgian international goalkeeper Geert De Vlieger on a free transfer.

De Vlieger, 32, arrives on a free transfer from Dutch side Willem II, where he snubbed a new five-year deal to sign a two-year contract at the City of Manchester Stadium.

With 42 caps for Belgium he will provide experienced back-up to England number one David James.

He said: "My contract in Holland ended this year and I was offered a new five-year deal but I wanted something new.

"I was looking for a new challenge and Manchester City came in for me with a two-year deal .