LONDON (Reuters) - A small British energy supplier, called Spark Energy Supply Limited, has ceased to trade, regulator Ofgem said on Friday, promising to find a new supplier for customers soon.
A number of other small energy providers have gone bust in Britain, prompting Ofgem on Wednesday to propose financial and customer stress tests for energy suppliers wanting to enter the market.
On Friday it said the outstanding credit balances of Spark Energy's 290,000 customers would be protected and there would be no disruption to supplies. It did the same for the 129,000 customers of Extra Energy on Wednesday.
A push to increase competitiveness in Britain's energy market has reduced the market share of the six largest companies to 70 percent from over 95 percent in recent years, with 60 smaller independent companies in operation.
However, their rapid rise has led to questions over their viability as, with less capital available to make long-term hedges, some may have been vulnerable to soaring wholesale commodity price rises.
(Reporting by Sabina Zawadzki; Editing by Susan Fenton)