Griffiths has been linked with United for some time but has finally put pen to paper to end the speculation.

It is another blow for the Jets who have lost skipper Jade North to North Queensland Fury and seen marquee man Edmundo Zura pack his bags and head back to Ecuador.

Griffiths told the Herald: "People have to realise it is a business now.
Players come and go. The package they offered was really good. Financially it was a big step up from what I am on here and they also gave me some options that Newcastle would not with regards to capping transfer fees."

Griffiths revealed he had spoken to brother Joel about his decision but felt he had to do what was best for himself and his fiancee.

He will remain with the Jets for the group stage of the 2009 Asian Champions League though.

He said: "I have finalised things now, and I can concentrate on the rest of the season with Newcastle.

"That is all I want to focus on. I want to make sure we are in the top four and then go well in the Asian Champions League."

It is thought the Gold Coast deal allows for an overseas switch should there be interest in Griffiths down the track.