The European Union's antitrust office has issued an objection to a proposed merger of the music units of Japan's Sony Corp. and Germany's Bertelsmann AG. The companies now have two weeks to respond to the claims that a 50-50 tie-up would result in unfair dominance in the recording industry. Bertelsmann's music publishing group, BMG, said it was examining the EU's concerns, but said in a statement on Tuesday that "the merger will not impede competition." If the two companies do go through with the deal, it would leave only four global music majors holding about 80 percent of the market. Similar concerns derailed merger plans between EMI Group PLC and Warner Music Group Inc. four years ago. The EU has until July 22 to reach a final decision regarding the merger.