BRUSSELS (Reuters) - European Union antitrust regulators have suspended their investigation into Siemens' (>> Siemens AG) $7.6 billion bid for U.S. oilfield equipment maker Dresser-Rand Group (>> Dresser-Rand Group Inc.) while waiting for "important information" from the German company.

The European Commission suspended its probe on March 19, a filing on its website showed on Wednesday.

"The clock was stopped because there is an important piece of information that the Commission has requested from the parties and has not been submitted yet," Commission spokesman Ricardo Cardoso said.

Siemens said the delay would not affect the deal.

"We're on schedule and still expect the transaction to close in the summer of 2015 or earlier. Please understand that we can’t comment in further detail on ongoing proceedings," spokesman Alexander Becker said.

Last month the EU competition authority voiced concerns that the merged company would compete only with General Electric (>> General Electric Company) in turbo compressors and drivers for trains.

Such concerns usually ratchet up the pressure on companies to offer concessions such as asset sales or make it easier for rivals to use their technologies or patents in order to ease regulatory concerns.

Siemens, Europe's largest engineering group, hopes the deal will boost its presence in the U.S. shale oil and gas industry.

(Additional reporting by Georgina Prodhan in Frankfurt; editing by Susan Thomas)

By Foo Yun Chee