The growing international crisis over Iran's nuclear programme could trigger a catastrophic oil price spike, sending crude prices over $100 a barrel, senior Wall Street analysts are warning.

With prices already at around $72 a barrel, such an increase could mean drivers facing prices of 110p a litre on forecourts, according the the Petrol Retailers Association. Last week Lord Browne, chief executive of BP, warned that prices could rise to £1 as he unveiled bumper $5.27bn profits for the first quarter.

Shell is also expected to announce close to record numbers next week, with analysts expecting profits around $5.57bn, driven largely by the oil price.

A single political shock could be enough to send oil markets into panic, said Adam Sieminski, senior energy economist at Deutsche Bank in New York. 'If we have one more big problem we are going to have triple-digit oil prices.' Sieminski points to confrontation with Iran, a worsening of the situation in Iraq or a recurrence of devastating hurricanes in the Gulf of Mexico as potential catalysts for a major rise.

Observer