"The window of opportunity is too close to look at buying into ERUs," said Erik Boonman, head of origination of energy, carbon and commodities at Fortis Bank Nederland. "Look how close were are to the end of Phase II. There is no confidence in the markets that places such as Russia, which constantly delay output, will be able to deliver the amount intended, even by 2011."

He adds that, taking legal fees into account, "it isn't really worth it for the investor".

ERUs are units of greenhouse gas