GENEVA - WORLD Bank chief Robert Zoellick on Monday warned that trade-distorting measures used by governments to stimulate their economies could 'spin out of control' as unemployment rises.

'High-income countries have used subsidies for troubled industries, while low-income countries are using selective increases in border barriers,' he said.

'These trends can easily spin out of control in coming months as unemployment rises,' he told a World Trade Organisation two-day conference on the 'Aid for Trade' process.

Pointing to signs of protectionism, Mr Zoellick cited examples such as the United States' 'Buy American' provisions in its stimulus package and Washington's move to re-introduce dairy export subsidies.

He also pointed to China's 'Buy Chinese' provisions.

'Government leaders need to recognise that they are playing with fire,' said Mr Zoellick.

Earlier, when opening the conference, United Nations chief Ban Ki Moon said trade must form part of global efforts to stimulate an economic recovery.

'Trade has long had tremendous potential as an engine of sustained economic growth and development. Today, trade can and must be part of our efforts to stimulate a recovery,' Mr Ban said.