A red traffic light is seen in front of an office building of Siemens AG in Munich Perlach May 30, 2014. ) is set to secure unconditional EU approval for its $7.6 billion bid for U.S. oilfield equipment maker Dresser-Rand ( The acquisition, Siemens' largest ever, will boost the trains-to-turbines group's presence in the United States and the shale exploration boom there, and also take it a step closer to rival General Electric ( The European Commission warned in February, when it opened a full-scale investigation, that the deal might reduce competition and drive up prices.