screenshot by Stephen Shankland/CNET

The Federal Trade Commission may not have enough evidence of harm to consumers to proceed with an antitrust claim against the heart of Google's business, search, Bloomberg reported.

Google faces antitrust investigations from the U.S. FTC and from the European Commission, both going on for many months and both carrying the potential to wreak havoc with Google's search business. At the heart of the issue is whether Google gives unfair prominence to its own properties -- YouTube, Google Flight Search, Google Images, Google Shopping, Google Maps, and more -- at the expense of other businesses.

Regulators aren't sure they have enough evidence for an antitrust lawsuit and are examining whether consumer benefits of Google's search approach outweigh harm to competitors, Bloomberg reported, citing three unnamed sources.

FTC spokesman Peter Kaplan declined to comment on the report. CNET has contacted Google for comment and will update this story if it responds.

Legal observers expect FTC and EC action of some sort by the end of the year in the Google case, but it's not clear yet whether that might be a settlement or more serious actions such as the FTC suing or the EC filing a statement of objections.

Other subjects are involved besides search results -- for example, difficulties in placing search ads at other sites besides Google and possibly Google's terms for letting phone makers use the Android operating system -- but those are peripheral compared to the search fairness issue.

Those rallying opposition to Google include two industry groups, FairSearch.org and Icomp; Microsoft is a memer of both groups, but other companies involved with the groups include comparison shopping sites Foundem and Nextag and travel sites Kayak, Expedia, TripAdvisor, and Hotwire.

Updated 6:48 a.m. PT with FTC declining to comment.