This is the third tranche of gas to be released by British Gas under a four-year programme agreed with the Office of Fair Trading in 1992.
The 500 million therms - equivalent to about 3 per cent of the quantity distributed annually by British Gas - will be used mainly to supply industrial and commercial customers in the firm contract market.
Since the release programme began 102 companies have successfully applied for gas. More than 70 per cent of the firm gas market is now accounted for by independent suppliers. There is also evidence that British Gas is losing customers on interruptible contracts to rivals.
The watchdog Ofgas, responsible for overseeing the programme, plans to invite independent gas shippers to apply for the gas early next year.
Norman Blacker, managing director of gas business at British Gas, said: 'We expect these additional quantities of release gas to stimulate competition still further.'
British Gas will not face full competition in the domestic market until 1998.Reuse content