LONDON - Carbon offset retailers and brokers have seen increased interest in and demand for voluntary carbon credits this month, particularly from the United States.

Since this year started we have seen a huge amount interest -- mostly from the U.S. -- in carbon credits and it won't be long before the voluntary market worldwide begins really to gain some momentum, said Matthew Sullivan, chief executive of carbon offset retailer the Carbon Advice Group.

The unregulated voluntary market operates outside mandatory emissions cut schemes such as the United Nations' Clean Development Mechanism or the European Union's Emissions Trading Scheme.

It relies on businesses to self-regulate their carbon emissions in the absence of a legally binding climate agreement and individuals' need to offset their carbon footprint.

Brokers MF Global saw an increase in demand for Voluntary Carbon Standard (VCS) and Gold Standard credits this month.

Interest in pure-VCS credits, particularly from U.S. buyers, has increased markedly, it said in a brokers' note.

Prices for Gold Standard spot voluntary emissions reductions were around 6.50 to 7.50 euros a tonne. Pure Voluntary Carbon Standard credits were $2-$2.50, while recent vintage pre-CDM voluntary carbon units were $3-$4.

Climate change