Federal authorities are examining whether multiple insider-trading rings reaped illegal profits totaling tens of millions of dollars, The Wall Street Journal reported on Saturday, citing people familiar with the matter.

The three-year criminal and civil investigation could result in charges by the end of the year, the Journal reported. A federal grand jury in New York has heard evidence, the paper said. Since the investigation isn't finished, it's unclear what charges, if any, may be brought.

One focus of the criminal investigation is whether independent analysts and consultants who work for companies that provide "expert network" services to hedge funds and mutual funds passed along nonpublic information, the Journal reported. Such companies set up meetings and calls between current and former managers and traders who want an investing edge.

The newspaper said one firm under examination is Primary Global Research LLC of Mountain View, Calif., which connects experts with investors seeking information in the technology, health-care and other industries. Chief Operating Officer Phani Kumar Saripella declined to comment to the Journal. The firm's website says Saripella and the firm's CEO previously worked for Intel Corp.

Prosecutors and regulators are also examining whether bankers from Goldman Sachs Group Inc. leaked information about transactions, including health-care mergers, to the benefit of certain investors, the Journal reported, based on anonymous sources. Goldman declined to comment to the newspaper.

The examination includes independent analysts and research boutiques. John Kinnucan, a principal at Broadband Research LLC in Portland, Ore., described a visit by FBI agents in an Oct. 26 e-mail to roughly 20 hedge-fund and mutual-fund clients. The Journal said Kinnucan confirmed that he wrote the e-mail, which was addressed to traders at firms including the hedge funds SAC Capital Advisors LP and Citadel Asset Management, and mutual-fund companies Janus Capital Group, Wellington Management Co. and MFS Investment Management. None of the firms commented to the Journal, and it isn't known whether they are under investigation for their business with Kinnucan.