Investment banks have stepped into the breach as major liquidity providers in the energy markets since the demise of market-maker Enron in late 2001. Barclays Capital, for one, expanded its commodities business by breaking into the natural gas and electricity markets at the end of that year.

The bank moved quickly in Europe in 2002, by hiring a team of experienced traders and marketers to build a UK and continental Europe power and gas business, says Richard Lewis, BarCap’s European head of