By Susanna Twidale LONDON (Reuters) – The approach of Britain’s energy regulator to awarding new supply licences and monitoring companies increased the risk of firms failing and contributed to higher energy costs for struggling households, a parliamentary watchdog said on Wednesday. Some 28 British energy suppliers have collapsed since June last year, squeezed by record high wholesale energy prices and the price cap set by the regulator, Ofgem, preventing them from passing on costs to customers. While Ofgem could do nothing about the soaring wholesale prices, its actions increased the risk and…