In early morning trading on 11 September, the price of West Texas Intermediate oil was $101.91 on the New York Mercantile Exchange, near a five-month low and a 30 per cent drop on the all-time record of $147.27, set exactly two months earlier.

On 9 September, oil cartel Opec cut production by 520,000-barrels-a-day (b/d) to abide by official production levels with consumer body, the International Energy Agency, saying the drop in output would prove unhelpful to a fragile market.

Adding to price tension was the surge of the US dollar to its highest level against the euro since October 2007, with many traders selling out of commodities.

Investment bank Barclays Capital says the $100 level is shaping up as a “soft floor” to trigger price-defensive actions.

“While we believe Saudi Arabia would be perfectly happy with prices in the $90 to $100 range, it seems that other Opec members wished to give a stronger signal,” says the bank.