Google is rolling out changes to how it shows shopping search results across Europe from Wednesday in a bid to avoid fines from a seven-year antitrust probe.

The search giant promises to treat its own shopping service the same as rivals when they bid for ads at the top of a search page. The company is offering space in an ad panel at the top of its search page to shopping-search services which can bid via an online auction for a slot to show a photo and a link to a retailer. These slots are currently sold by the company's own Google Shopping service to retailers. The Google Shopping unit will operate independently from its parent and must bid against rivals from its own revenues, without financial aid from Alphabet's Google.

"We're giving comparison shopping services the same opportunity to show shopping ads from merchants on Google's search results pages as we give to Google Shopping," said Google spokesman Al Verney.

"Google Shopping will compete on equal terms and will operate as if it were a separate business, participating in the auction in the same way as everyone else," he said.

The European Commission slapped a record 2.4-billion-euro ($2.8 billion) fine on the world's most popular internet search engine in June and told the firm to stop giving an unfair advantage to its shopping service.

Google, a unit of the U.S. firm Alphabet, has until Sept. 28 to halt this anti-competitive practice or face a penalty up to 5 percent of its average daily worldwide turnover.