The commission began its investigation last November, after concerns the merger would overly restrict competition in the online advertising sector.
There were also complaints by third parties, including Microsoft, over 's position in ad serving and 's position in search advertising.
However, the commission has stated today that the merger would be unlikely to have harmful effects on consumers, either in ad serving or in the online advertising market.
It said: "The commission's in-depth market investigation found that Google and DoubleClick were not exerting major competitive constraints on each other's activities and could, therefore, not be considered as competitors at the moment."
The deal has already been approved in the US by the Federal Trade Commission. However, critics have said that it will put too much sensitive information about what people are doing on the internet into the hands of one company.
Google's share price was up when the US markets opened this morning, rising by more than 4% to $430.67.