Mumbai, Sep 7 - In sharp variance to the findings of an expert panel set up by India, a UN agency says futures trading in commodities affects spot prices of physical markets across the world, calling for concerted regulatory action by governments.

Released worldwide Monday, the report by the United Nations Conference on Trade and Development (Unctad) blames large financial investors for influencing commodity prices through futures trading, without regards to the actual demand-supply situation.

Incidentally, a government panel headed by economist Abhijit Sen had said in a report last year that there was no empirical evidence to suggest a link between futures trading and rising prices in India.

Unctad's annual Trade and Development Report says commodities were being treated as merely an asset class and futures trading in its current form held the power to shift prices, irrespective of the supply-demand situation.

'Individual market participants may take position changes that are so large relative to the size of the market that they move prices, which can be called the weight-of-money effect,' says the report.

The UN agency, accordingly, calls for international collaboration among countries and regulators to bring about a comprehensive framework to deal with excessive speculation that has been blamed by several countries including India for the surge in food prices.