Ministers from major oil-producing and -consuming economies in Asia and the Middle East called for more investments in the energy sector Sunday while limiting "speculative" money to avoid extreme volatility in oil prices.

Representatives from Japan, China, India, Iraq and Saudi Arabia confirmed that demand for energy will grow in most of the region in the medium and longer terms, and investments in the sector will be "indispensable" to balance demand and supply in the future, the statement said.

"Participants affirmed that adequate and continuous investment throughout the energy value chain is essential as a means to balancing supply and demand in the future," said the chair's summary released after the Third Asian Ministerial Energy Roundtable held in Tokyo.