Selling public assets has created unregulated monopolies that hurt productivity and damage the economy, according to Australia's consumer and competition tsar, who says he is on the verge of becoming a privatisation opponent.

In a blistering attack on decades of common government practice, Australian Competition and Consumer Commission chairman Rod Sims said the sale of ports and electricity infrastructure and the opening of vocational education to private companies had caused him and the public to lose faith in privatisation and deregulation.

ACCC chairman Rod Sims says privatisation is hurting productivity. Credit:Vince Caligiuri

"I've been a very strong advocate of privatisation for probably 30 years; I believe it enhances economic efficiency," Mr Sims told the Melbourne Economic Forum on Tuesday.

"I'm now almost at the point of opposing privatisation because it's been done to boost proceeds, it's been done to boost asset sales and I think it's severely damaging our economy."