High oil prices pose a serious threat to the global economy, and could cut world growth by 0.5 percentage points, and that of poor countries by even more, World Bank president Mr James Wolfensohn said yesterday.

"When you get into the range of $30 (€35) to $35 per barrel, it clearly has a significant negative effect on world economic output," Mr Wolfensohn said in an interview with the International Herald Tribune. "A $10 (a barrel) shift in oil prices can make a difference and result in one-half percentage point lower growth at world level," he said.

"For developing countries as a group, the higher price suggests three-quarters of a percentage point lower growth," he said.

Oil prices rose again yesterday as brewing tensions in the Middle East prompted the United States to warn Iraq that it would use military force if Baghdad threatened neighbour Kuwait.

London Brent crude rose 4.5 per cent to $33.78 a barrel for a gain of $1.49 and US light crude gained $1.48 to $35.55 a barrel.