By Julia Payne BRUSSELS (Reuters) -The European Commission has asked the EU’s energy regulator ACER to examine whether a tariff Germany added to its natural gas exports distorts the bloc’s single market in a possible breach of competition rules, three sources close to the matter said. The tariff is a legacy of the European energy crisis that peaked in 2022 after Moscow cut gas flows to Europe following its invasion of Ukraine and an undersea explosion shut the Nord Stream pipeline from Russia to Germany – the route for 15% of Europe’s gas imports. That year, the Commission issued EU-wide gas s…