The U.S. search giant said it would put its brand on any of its own maps, stock quotes, airline flight details or other pieces of information returned with search results, Britain's Financial Times reported Tuesday.
The proposal is seen as Google's attempt to assuage European regulators' fears that the company is unfairly squeezing out other specialist information services on the Web.
Google's competitors opposed the proposal, saying Google could still stifle competition by promoting its own services over others'.
"Google would still be able to put its competitors on page 35 [of its search results], so any solution would have to go much further," said Ben Edelman, an associate professor at Harvard University who has been critical of Google's search and advertising practices.
Google's practice of displaying its own services directly in prominent places in its search results pages -- for instance, by putting a stock quote from Google Finance at the top of a page, where most users click first -- drew the attention of European regulators, who began an investigation in May.
Google, although declining to comment on its labeling proposal, said: "We continue to work cooperatively with the European Commission."