The European Commission invited public comments Thursday on remedies submitted by US Internet giant Google to resolve EU concerns over its dominant position in the online search and advertising market.
The Commission, the EU's executive arm, said it would take the comments into account in its own review of Google's proposals and could make them binding on the company.
The move, known as a 'market test,' was welcomed by rival companies who say they have lost out unfairly to Google, but some wanted more.
FairSearch, a group of major high-tech companies including Microsoft and Oracle, said there had to be a level playing field in a European market held more than 90 percent by Google.
"We have always said that Google should subject its own products to the same rules it uses to rank and display other websites," FairSearch said in a statement.
"That is the best way to meet the Commission's stated goals of restoring consumer access to a competitive market," it said, adding that since Google had had a year to develop its proposals, "we think it is only fair that outside experts have more than a month" to examine them.
In response to the announcement, Google said: "We continue to work cooperatively with the European Commission."
The Commission said it had four areas of concern, firstly that a search on Google will favour results linked to the company's specialised services, such as surveys of restaurants of hotels.
Google was also using "without consent" original content from third party websites and obliging such sites to "obtain all or most of their online search advertisements" from the company, it added, essentially making Google the middle man between websites and advertisers.
Finally, Google was placing "contractual restrictions on the transferability of online search advertising campaigns," the Commission said.
Combined, "these practices could harm consumers by reducing choice and stifling innovation in the fields of specialised search services and online search advertising," the Commission said.
To remedy these concerns, Google proposed for a period of five year to make users clearly aware if they were being directed to another Google service it said.
Google would also offer "all websites the option to opt-out from the use of all their content in Google's specialised search services," meaning that companies could restrict access to their data and offerings.
Crucially, Google would also provide newspaper publishers with a mechanism to control the "display of their content in Google News," the Commission said
The company further committed 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."
It would also "no longer impose obligations that would prevent advertisers from managing search advertising campaigns across competing advertising platforms."
Brussels launched its investigation of Google in November 2010 following a complaint by several companies, including Microsoft.
However, the US Federal Trade Commission recently dropped a similar investigation, saying it lacked a legal basis to bring a case against Google.
Critics say Google dominates the Internet search market and the advertising that goes along with it.
The probe is one of a series of regulatory problems facing Google.
Earlier this month, FairSearch complained to the Commission about Google's offerings for its Android-powered mobile phones.
Six European countries, including France and Britain, have also launched joint action against Google to get it to scale back new monitoring powers that watchdogs believe violate EU privacy protection rules.
The public has one month to submit comments. A company found at fault in an EU anti-trust probe can face fines of up to 10 percent of its total annual sales.