Prominent Adelaide lawyer Greg Griffin says the sale of the A-League side Adelaide United was the result of a handshake agreement he had with one of his fellow owners Robert Gerrard.

The club announced on Wednesday there had been an immediate ownership change, with a group of predominantly European businesspeople with commercial activities in Europe, Australia and Asia investing in the Reds.

It means the end of the line for Griffin and Gerrard, who have plunged substantial financial resources into the club.

"I had no desire to sell to be blunt, but you know, basically Rob and I had a handshake agreement nine years ago that we came together and we'd leave together and Rob had taken the view that he'd done as much as he thought he could do," Griffin admitted.

The investors are believed to have paid more than $10 million to take over and plan to take their time becoming familiar with the Reds, before announcing their future plans in "due time".

"They are football people, I know that, and they want to integrate Adelaide United into sort of a global football family, which involves a European club, a Chinese club and (an) Australian club — and I think that's a positive thing," Griffin said.

Since taking over in 2010, Griffin says the club initially lost substantial amounts of money, before he took a more hands-on role in recent years and the franchise started breaking even.

But Adelaide hasn't had the financial might of other A-League clubs and couldn't afford to attract the more expensive marquee signings from overseas.

Greg Griffin said the new owners want to integrate Adelaide United into a "global football family". ( AAP: Ben Macmahon (file photo) )

Griffin said the Reds have been paying marquee players up to $600,000 a season, but the new owners may be able to pay more than $1 million to attract quality signings.

"I suppose the test is whether they go off and bring in, as I understand is their intention, some very good quality Dutch players for example, which I think that'd be good for the Reds," Griffin said, admitting he'll be in the grandstands as a Reds supporter in the future.

Griffin has been an outspoken critic of the Football Federation Australia (FFA) during his United days and is dismayed at the way the FFA has administered soccer overall and the A-League in particular.

But he sees light on the horizon.

"It's in the doldrums because it's been poorly marketed and run by the FFA," he said.

"So what the last 12 months has been about is trying to change the congress so that we can get a board that's much more collaborative with the elite game, which involved us and the player union.

"I expect within 12 months there'll be an independent A-League, which will be run essentially by the clubs, giving the players and the referees a far greater say.

"I think that'll be the catalyst for expansion and growth."

While he supports the eventual awarding of a second A-League licence in Adelaide, Griffin said the likes of interested top state league clubs like Adelaide City and West Adelaide would not work.

"I don't think clubs who have put their hands up have any prospect of being finally able to run an A-League club, I mean they won't be chosen because they'll go broke and all they'll do is upset the ecosystem which has been in place for so many years," Griffins controversially stated.

"I've never said it couldn't work, I just said you need to have the right people in control of it and that's not any of the existing clubs and I think it's a folly for them to continue with that idea."

Griffin said the new owners have guaranteed that all staff will keep their jobs while players' contracts will also be honoured.

On the field the Reds are still trying to secure a finals berth, but don't play again until Friday, March 16, against Melbourne City.