The Organisation for Economic Cooperation & Development (OECD) has revised its growth outlook for the Indian economy from "below trend" to "slowing down", and warned that the worst mightn't be over for the world's second most populous country.

The Paris-based think tank said that the Indian economy is suffering rate of economic growth.

In terms of long-term trend of economic activity, which is put at 100, India scored 97.2. It was the lowest level recorded by the economy in the last five months.

In its report, the think tank said, "In China, India and to a lesser degree in Brazil, the composite leading indicators (CLIs) point to growth below trend."

In the third quarter of the current fiscal year, Indian economy grew at a rate of 4.5 per cent. In the full year through March 31, the economy is expected to grow at just 5 per cent - the lowest rate of growth in around a decade.

India's union finance ministry has projected a growth rate of between 6.2 per cent and 6.7 per cent in the next fiscal year.

The think tank also said that economic outlook in big industrialized economies is improving, with the US and Japan leading the way. With a reading of 100.9, the US showed the strongest improvement; while Japan's economy climbed to 100.6.