European Union (EU) competition regulators have approved a € 1.49 billion fine for Google's Alphabet for blocking online searchers.
This marks the company's third penalty in two years.
Last year, the EU's competition regulator imposed a record fine of 4.34 billion euros on Google for using its popular Android operating system to block rivals.
This followed a fine of 2.42 billion euros in 2017 for harming rivals of comparison shopping sites.
The European Commission said the fine today accounted for 1.29% of Google's turnover in 2018.
The latter case concerned sites such as newspaper or travel sites with a search function that produces search results and search ads. Google AdSense for search provided these search ads.
The misconduct included preventing publishers from placing competitors' search ads on their search results pages.
This forced them to reserve the most profitable space on their search results pages for Google ads and also required them to seek written approval from Google before making changes to how rival ads were displayed.
The Google AdSense advertising case was triggered by a Microsoft complaint in 2010.
Both companies subsequently filed complaints against each other in 2016.
"Today the Commission fined Google EUR 1.49 billion for the illegal abuse of its dominant market position for the intermediation of online search ads," said EU competition commissioner Margrethe Vestager.
The commissioner said that Google "cemented its domain in online search ads and protected itself from competitive pressure by imposing anti-competitive contractual restrictions on third-party sites."
"The misconduct lasted more than 10 years and denied other companies the possibility of competing on merit and innovating – and consumers the benefits of competition," he added.
But Commissioner Vestager has cautiously welcomed Google's attempts to boost rivals and offer Android users a browser option and search applications to comply with their orders in two separate cases.
"We see positive developments both in the case of purchases and in the case of Android," Vestager told a news conference.
In a sign that Google's regulatory issues may not be on the rise, Vestager said it is still investigating its actions in the search market for jobs and local searches after complaints.
Kent Walker, senior vice president of global affairs at Google, said the company has always agreed that healthy and prosperous markets are in everybody's best interest.
"We have already made a wide range of changes to our products to address the concerns of the Commission. In the coming months, we will make further updates to give our rivals more visibility in Europe," Walker said.