British bank Barclays has quit the energy trading market, joining a number of other banks that have done the same in recent years, Reuters reports. The exodus from the energy market has raised concerns among oil and other energy producers that falling market liquidity will restrict their ability to use derivatives to hedge their prices. A growing scarcity of counterparties could force up hedging costs to unaffordable levels. Barclays was ranked a top-five player in the energy market.