The fate of Google’s controversial acquisition of online advertising group DoubleClick is set to be decided early next year by regulators in Europe, following Thursday’s decision by US antitrust regulators to clear the deal without conditions.

The expected decision by the commissioners at the Federal Trade Commission, who approved the deal by four to one, brings Google an important step closer to sealing a $3.1bn acquisition that is central to its broader ambitions in the online advertising market.