Google has agreed to alter its search results in the light of a European investigation into whether it unfairly promoted its own services.
The firm said that it will more clearly label results from YouTube, Google Maps and its other sites.
It also agreed to display links to rivals close to where it displayed its own services on its results page.
EU regulators are asking for feedback and have proposed that the concessions be tested for a month.
If the European Commission accepts them, they will become legally binding for the next five years.
As part of the agreement, Google will clearly separate promoted links from other web search results as well as displaying links to three specialised search rivals "close to its own services in a place that is clearly visible to users".
"The objective of this process is to try to see if we can achieve a settled outcome in this antitrust investigation," said Commission spokesman Antoine Colombani.
But the Microsoft-backed lobby group Initiative for a Competitive Marketplace (Icomp) was not convinced the changes went far enough.
"It is clear that mere labelling is not any kind of solution to the competition concerns that have been identified. Google should implement the same ranking policy to all websites," it said.
It added it would comment further once it had fully evaluated the proposals.
Dominant in Europe
Other concessions being offered by Google include:
* To offer all websites the option to opt out from the use of all their content in Google's search services, while ensuring that any opt-out does not "unduly" affect the sites' ranking in its general results
* To offer specialised search sites which focus on product search or local search the option to mark certain categories of information so that they are not indexed or used by Google
* To no longer include in its agreements with publishers any written or unwritten obligations that would require them to source online search advertisements exclusively from Google
* To no longer restrict advertisers from running search advertising campaigns across rival ad platforms
An earlier US Federal Trade Commission investigation into how Google displayed links to its services concluded there was no competition issue.
Explaining why it took a different view the Commission said: "Bing and Yahoo represent a substantial alternative to Google in web searches in the USA; their combined market share is around 30%. In contrast, Google has been holding market shares well above 90% in most European countries."
"The way Google presents its web search results therefore has a much more significant impact on users and on the competitive process in Europe than it does in the USA."