A storm of outrage over Luxembourg’s role in helping global companies avoid tax plunged its former leader into controversy in his first week running the European Commission, the EU body that polices tax abuses. Jean-Claude Juncker, 59, who took over as president of the EU executive after more than two decades as finance minister and prime minister of the tiny Grand Duchy, pulled out of a speaking engagement on Thursday. He repeated through a spokesman a remark made the previous day denying a conflict of interest and saying he would not hinder existing EU investigations of Luxembourg.