Google must respond by July with regards to the ongoing antitrust investigation by the European Commission for Competition Policy, presenting realistic and workable proposals in order to avoid huge fines, which could potentially be as much as 10% of the internet search firm's annual income.

"By early July, I expect to receive from Google concrete signs of their willingness to explore this route," said Joaquin Almunia, the Commission's vice president during an address at a conference in Switzerland at the weekend.

The threat of a fine, which would reach as high as $4 billion comes as the first stage of the European antitrust investigation nears its end. The investigation dates back to November 2010 and was started after complaints from rivals, including Microsoft, that the search company was abusing its dominant market position as well as favoring its own advertising services when presenting search results.

"In case we engage in negotiations to address our concerns and the proposals we receive turn out to be unsatisfactory, formal proceedings will continue through the adoption of a statement of objections," said Almunia. "I strongly believe that users and competitors would greatly benefit from a quick resolution of the case."

Despite the Commission's threats, Eric Schmidt, Google's executive chairman remained defiant when commenting about the investigation last month at the firm's Big Tent conference in Hertfordshire, England.

"He [Almunia] is encouraging us to have a conversation [and] we completely agree" Schmidt said, according to the Telegraph. "We disagree that we are in violation. Until they are precise about what areas of the law we have violated, it will be very difficult for me to speculate."

Amit Singhal, Google's senior vice president of Engineering also published an extensive blog post on the firm's Public Policy Blog on Friday, titled "setting the record straight: competition in Search" in which Singhal dispelled many common claims in relation to accusations of unfair competition.