By Foo Yun Chee BRUSSELS (Reuters) – EU antitrust regulators on Friday dropped their year-long investigation into Kingspan’s proposed acquisition of Slovenian rival Trimo after the Irish insulation maker abandoned its bid. The European Commission had previously said the deal, announced two years ago, could significantly reduce competition for mineral fibre sandwich panels in the Czech Republic, Denmark, France, Hungary, Slovakia, Slovenia and the UK, as both companies are direct rivals. Kingspan and Trimo are both leading companies in the market for mineral fibre sandwich panels, which are use…