When UK natural gas prices on the APX gas UK exchange went negative in late 2006, commercial director - and marathon runner - Les Male admits his legs "were a little wobbly". But he says the incident was a testament to the transparency and proper functioning of the market. "It's a simple economic formula of supply and demand: with a large (new) supply coming from a Norwegian field and demand at typical levels, the market performed as you'd expect."

Male says the faultless handling of negative