Qantas, Emirates, Virgin Australia and other airlines are under pressure to reduce fuel surcharges on tickets after an 18 per cent drop in jet kerosene prices over the past four months.

Australia's largest travel agent, Flight Centre, said airlines had been quick to increase surcharges when jet fuel costs rose but were slow at reducing them when costs fell.

Australia's largest airline imposes a fuel fee of $340 for a one-way economy and premium economy ticket to the US.

"History shows that surcharges are much more likely to rise than decrease," Flight Centre spokesman Haydn Long said. "If it was government-controlled and reviewed monthly, you would get a more legitimate amount."

Since June, the spot price for jet fuel in Singapore has fallen from $US125 a barrel to about $US103.