Oil prices will rise modestly towards $85 a barrel next year despite market expectations that they will return to above $100 a barrel, the world's largest oil trading house has forecast.

Ian Taylor, chief executive of Switzerland-based Vitol, said a price band between $70 and $85 a barrel was "widely viewed as meeting producers' needs while being simultaneously 'acceptable' to consumers".

"We see prices progressing to the higher end of this range over 2011," he writes in today's Financial Times. But he warned that surpluses in production and refining capacity will keep prices "in a relatively narrow band" next year. "The concept of a price ceiling exists today in a way that it simply didn't when prices rose to $150 in the middle of 2008."

Vitol is largely unknown outside the energy industry, yet it trades more than 5m barrels a day of oil - equivalent to the daily imports of Germany, France and Italy combined. Its outlook is important because it is at the centre of global flows, and its wide business relationships help it anticipate price cycles.

Together with traders Glencore, Trafigura, Gunvor and Mercuria and oil companies such as BP, Royal Dutch Shell and Total, Vitol dominates global energy trading. Its moderateforecast comes as Opec is likely to leave its production levels unchanged when it meets in Vienna on Thursday.

Wilson Pastor-Morris, the Ecuadorean natural resources minister who will chair the Opec meeting, said there was a "consensus" behind output levels. "The quotas will be maintained. No changes are foreseen," he said, adding Opec was "happy" with current prices.