(Reuters) - Britain's energy regulator said on Thursday it has four cases open against UK energy suppliers over their poor handling of customer complaints, following a bi-annual survey.
Energy market regulator Ofgem said it has opened compliance cases into First Utility, Ovo Energy and Utilita and is expanding a recent case on Iberdrola SA's <IBE.MC> ScottishPower.
The regulator also said it was requiring all other domestic suppliers surveyed - Centrica's <CNA.L> British Gas, Innogy SE's <IGY.DE> Npower, Utility Warehouse, SSE <SSE.L>, EDF's <EDF.PA> EDF Energy, E.ON <EONGnDE> and Co-operative Energy - to provide improvement plans on how they will deal with complaints and provide appropriate updates.
(Reporting by Arathy S Nair in Bengaluru; editing by Nina Chestney)
