According to Reuters, the European Commission, the executive arm of the EU, had organised a meeting of national competition authorities on Tuesday (10 July) to inform them of the announcement, which is said to include a record-breaking fine.
But sources said that the meeting had now been postponed to 17 July. Wednesdays are the days on which the EU executive normally announces decisions taken at its weekly meetings.
On 8 June, reports said that the fine was due to be announced in the second week of July.
Whenever it is announced, the fine would be the second levied by the EU on Google. In June last year, Google was fined €2.42 billion (US$2.7 billion) for allegedly abusing its search engine dominance to give illegal advantage to its own comparison shopping service. The company has appealed the decision.
The company is likely to face an EU fine over its AdSense advertising system, according to reports.
The EU has also floated the idea of breaking up Google into a number of smaller units, with EU competition commissioner Margrethe Vestager saying the political bloc harbours "grave suspicions" about the firm's dominance of the search market.
In February, the Competition Commission of India hit the company with a fine of 135.86 crore rupees (about US$21.1 million) for "abusing its dominant position in online general Web search and Web search advertising services in India".
Google and other big multinational technology companies are also under pressure over alleged tax evasion, with the EC having unveiled a proposal to tax these companies at a rate of 3% as an interim measure.