Forde has Republic of Ireland ambitions

The 26-year-old from Galway passed a medical and agreed personal terms last month, but had to wait for the transfer window to open for the move.

Forde, who re-joined Derry two years ago after being released by West Ham United, hopes the move can earn him a Republic of Ireland call-up.

"I feel I have unfinished business in the UK and I want to push for an international spot," he told BBC Sport.

He added: "Dave Jones wants me to challenge Neil Alexander for the number one spot and it is certainly something I think I can do.

"Exciting things are happening at Cardiff - they are near the top in the Championship and they've got news of a new 30,000 stadium.

"It's a club going in all the right directions, it's a great city and I'm looking forward to the challenge ahead."

Forde enjoyed two successful years at the Brandywell.

"It's been an amazing two years with Derry and it was a tough decision to leave," said Forde.

"I spoke to Jim Roddy (chief executive) and Hugh McDaid (chairman) and they were very supportive.

"I've enjoyed myself immensely at Derry with a special group of players and it has been a special chapter in my life.

"But this is a decision I had to make. I look at what Kevin Doyle is doing a Reading and got a bit of inspiration from him."