Usd/maj. - A latest Economic outlook report fm Organisation for Economic Co-operation and Development (OECD) indicated that imbalances remaining at levels that wud have been unprecedented just a few years ago, the risk of disorderly exchange rate adjustment cannot be excluded. It also said that the world's key central banks will not need to start raising policy interest rates until late 2010 due to low inflation n economic slack, and can then proceed gradually.