Crude oil prices were swept to new nominal highs on Monday as Hurricane Katrina forced the shut down off about half of the Gulf of Mexico production and raised the spectre of disruption to refining.

Front-month US light crude rose around $5 a barrel to $70.80 in Asian trading but slipped back to $69.27 later. Gasoline and heating oil prices were also higher and gas traders said they were holding an emergency meeting after the forced shutdown of the Henry Hub - the delivery point for Nymex natural gas futures.