European Union regulators have brought yet another antitrust charge against Alphabet Inc's Google today, as it accuses the search giant of blocking advertising from rivals.

The third charge sheet against the tech giant says that it has abused its dominant position by artificially preventing third-party websites from displaying search advertisements from its competitors.

Google's "AdSense for Search" platform allows the company to act as an intermediary for websites such as those of online retailers and newspapers, with searches producing results that include search ads.

The European Commission also reinforced its previous charge that Google's own search results favour the Google shopping service.

Speaking in Brussels, European Competition Commissioner Margrethe Vestager said:

"Google has come up with many innovative products that have made a difference to our lives. But that doesn't give Google the right to deny other companies the chance to compete and innovate...

"We have also raised concerns that Google has hindered competition by limiting the ability of its competitors to place search adverts on third-party websites, which stifles consumer choice and innovation."

Fines up to 10% of Google's global turnover could be applied for each case if the company is found guilty of breaching antitrust regulations.

A Google spokesperson said:

"We'll examine the Commission's renewed cases and provide a detailed response in the coming weeks."