Three more newspapers said Tuesday that hyperlocal content provider Journatic used false bylines on a number of stories they have published, both in print and online.

The San Francisco Chronicle, Houston Chronicle and Chicago Sun-Times joined the Chicago Tribune in identifying the use of aliases in stories produced by Journatic, an ethics breach prompting growing concern as more newspapers outsource content.

"We've produced lots of stories in lots of places and we've since decided we're going to go in and look at every byline we've ever done," Journatic co-founder and CEO Brian Timpone said Tuesday.

Journatic's use of false bylines came to light during a national radio broadcast during the weekend. "This American Life," which is produced by Chicago public radio station WBEZ-FM, included a segment on aliases in several Journatic-produced stories that ran this year on TribLocal websites, prompting an investigation by the Tribune. That review is under way and expected to wrap up within the next week, according to executives.

"It is essential that our news report, no matter the source, is accurate and credible," said Gerould Kern, senior vice president and editor of the Tribune.

Publishing stories under false bylines is a violation of the Tribune's editorial ethics policy, according to executives, and is generally unacceptable throughout the industry.

Founded in 2006, Chicago-based Journatic employs about 140 overseas contract workers, mostly in the Philippines, who gather information online and then format it for more than 200 U.S.-based writers and editors, including 60 full-time staffers. The company provides editorial content for a number of newspaper groups and also owns Blockshopper.com, which publishes real estate news.

In April, the parent company of the Tribune made an investment of an undisclosed amount in Journatic, which provides coverage for TribLocal's 90 town websites and 22 weekly print editions.

Hearst Corp., which has worked with Journatic since 2009, also reviewed its outsourced content in the wake of the report, identifying false bylines at the San Francisco Chronicle and Houston Chronicle. Both papers offered an explanation to readers Tuesday.

The Houston paper said false bylines appeared in real estate stories over two years, in print and online. The San Francisco paper, which uses Journatic to produce a Sunday real estate section, found 32 stories with the alias Jake Barnes.

Timpone said Blockshopper went to aliases after writers began receiving threats from angry property owners, but the practice bled into its newspaper content operation. He said Journatic has discontinued its use of aliases on Blockshopper stories in the wake of the concerns from its editorial partners.

Timpone said Journatic has been providing custom real estate stories for the Chicago Sun-Times since 2010. A false byline was identified by the paper's previous owners more than two years ago, but the relationship continued unabated — until now. The revelations over the weekend prompted Sun-Times Editor-In-Chief Jim Kirk to pull the plug on future content from Journatic.

"With Journatic's partnership with the Chicago Tribune under way, we already were in the midst of winding down our relationship with Journatic's Blockshopper," Kirk said in an email Tuesday. "However, in light of the recent revelations of false bylines, we have decided to end our relationship immediately. Furthermore, prior Sun-Times leadership alerted Journatic of a false byline in April 2010. At that time, Journatic executives said they addressed the issue, and they have told us they are confident that no false bylines have run on content carried by Sun-Times Media since that date."

At least one industry analyst said the newspaper companies need to be more diligent in monitoring content partnerships.

"It is important that publishing companies be in charge of these technologies," said media consultant Ken Doctor. "Whether it's outsourced or in-sourced or however it works, it's important that those who know the rules of the trade — journalists — are in charge of making sure that the trust with the readers is kept, as we apply these new technologies."

Doctor said outsourced content providers like Journatic are here to stay, and properly employed, will help struggling newspaper companies do quality reporting more efficiently in the digital age.

Chicago-based Journatic freelancer Ryan Smith said his frustration over outsourced content spurred him to go to "This American Life" in April with his story. On Sunday night, after the radio broadcast reverberated across the journalistic world, he received his weekly Blockshopper assignments by email. He took the work.

rchannick@tribune.com

Twitter @RobertChannick