Crude oil prices ended an extraordinary week by rising for the first time above $90 a barrel after the dollar sank to a new low against the euro and some traders were forced to cover their bearish bets.

Persistent worries about tight supplies ahead of the winter peak season helped to push prices higher.

The 13 per cent price jump in the past 10 days has left oil close to its inflation- adjusted record high of more than $100 reached in early 1980 after the start of the Iraq-Iran war.

Nymex November West Texas Intermediate rose to a fresh all-time high of $90.07 a barrel – the sixth successive trading day that oil has touched a record high. By the close, profit-taking and a higher dollar pushed the price down 87 cents on the day to settle at $88.60, but it was still up 5.8 per cent on the week.

ICE December Brent hit a record high of $84.88 a barrel during the week, but closed on Friday at $83.79, down 81 cents on the day, for a weekly gain of 4 per cent.

The threat that the oil price rally might trigger an inflationary spike on top of the weakness of the dollar pushed the gold price to a fresh 28-year high of $770 an ounce while platinum rose to a record high of $1,454 an ounce.

The oil price rally was underpinned by financial flows as some traders were forced to cover bearish positions, particularly in the options market.

Edward Morse, chief energy economist at Lehman Brothers in New York, said speculators betting on further dollar weakness were also propping up the price.

“The surge in oil markets to $90 seems underpinned by issues more related to financial flows than fundamental factors,” Mr Morse said.

The dollar on Friday fell to a record low of $1.4319 against the euro. A lower dollar might result in producer countries, such as Saudi Arabia, trying to keep the oil price higher to compensate for more expensive imports priced in other currencies, such as the euro or sterling.

Nauman Barakat, senior vice-president at Macquarie Futures in New York, warned of massive positions on the December options calls – rights to buy oil at a certain price – at $90 and $100 a barrel, providing the backdrop for “additional upward impetus” next week.

The $90 a barrel options calls have been particularly popular in the past year among large energy consumers, such as airlines, transportation companies and utilities, that bought them to obtain protection against a large oil price jump.

“Wall Street traders who sold those options to consumer clients like airlines have been forced [now] to buy more spot oil to manage their options exposure,” Mr Morse said.

The Organisation of the Petroleum Exporting Countries suggested this week that it might use its head of state meeting in November in Riyadh to discuss a production increase.