UK Athletics have confirmed they have parted company with performance director Dave Collins with immediate effect.

Collins has left his post after being told his contract, due to expire next March, would not be renewed.

Niels de Vos, chief executive of UK Athletics, insisted Collins had left the sport in good shape despite their disappointing performance at the Beijing Olympics where they won four track and five medals - one short of their modest target of five

"It's not a reaction to the Games," De Vos said. "The reason behind it is that the performance director role needs changing. We need somebody in the role as a head coach.

"He [Collins] has led a radical overhaul of our performance systems, which will provide solid foundations on which we can build to ensure athletics fully meets the challenges of 2012 and beyond.

"Our planning for this next Olympic cycle got under way several months ago and this decision and any subsequent appointment is the culmination of this detailed process.

"It certainly is not a negative reflection on what has gone before, on the contrary there is no doubt we have made progress since 2004. However we now need to take the next step on the performance ladder and give ourselves and British athletes the very best chance of success at in 2012."

Collins said: "I am proud of what has been achieved in such a short space of time, due to some effective and committed teamwork.

"We now have the majority of our athletes operating out of four high performance centres surrounded by high quality and dedicated support teams and this will enable the sport to move towards greater success in 2012."

Charles van Commenee, who as chef de mission led Holland to their second most successful Olympics in Beijing, where they won 16 medals including seven golds, is being tipped to succeed Collins.

The Dutchman was a candidate after the retirement of Collins' predecessor Max Jones four years ago but, frustrated by the slowness of the interview procedure, instead accepted the job of performance director with his national Olympic committee.

"We haven't ruled anyone out for the post," De Vos said. "We won't be advertising. We have looked abroad, everywhere. I can't say who it will be. We will make an an announcement in the next few days."

De Vos revealed he considered making the decision to relieve Collins from his post earlier. "One year ago I was about 50 days into the post. I may have made a change earlier. No-one was available at the time," he said.

"This is not about me saying Dave wasn't good enough to do the job. The time was right. This is not a sacking, this is an evolution."