Bangkok, Mar 22: The Organization of the Petroleum Exporting Countries hopes to keep oil prices at a ''reasonable'' - a barrel, a level that supports their investments, the head of OPEC's research arm said on Thursday.

''We would hope to maintain prices as they are today, which are not only conducive to (our) investment but also to developing alternatives that will complement our efforts to meet the world's future energy needs,'' Hasan Qabazard told reporters.

''Prices today we believe are reasonable. We hope these prices will stay in the level where they are, between - a barrel. We believe they will stay in this range for the coming few years,'' he said in the Thai capital.

Many oil ministers and analysts have suggested that such a price range would be sufficient to justify the tens of billions of dollars of investment that OPEC nations are making to lift capacity, without endangering world economic growth.

But the group itself, which controls over a third of world output, has shied away from setting itself any formal price targets or reference bands, preferring to focus on inventory levels when making decisions about production policy.

Qabazard heads the producer group's research division, which gives OPEC ministers its supply and demand forecasts but does not usually take an active role in setting output policy.

''I believe the price will be stable because there is a lot of investment that has been taken, both upstream and downstream. These investments are coming online, almost 0 billion for more than 100 projects on the upstream alone,'' he said.

Earlier in the day, OPEC President Mohammed bin Dhaen al-Hamli, also oil minister of the United Arab Emirates, said the group did not have any ''trigger price'' that would prompt it to convene an emergency meeting before September.

OPEC agreed last week to keep its 1.7 million barrels per day (bpd) in output curbs in place for the time being.

Reuters