Portland's investigation into Uber's use of software to avoid regulators, which escalated dramatically when the city subpoenaed the ride-sharing company for records, came to an unremarkable conclusion Thursday.

The city found no evidence that Uber had used the piece of software the company called "Greyball" to avoid regulators or deny service to other riders since it started operating in Portland under an agreement with the city.

A New York Times report earlier this year revealed that Uber had identified certain users as likely city regulators and fed them false information during a period in 2014 when it was operating in Portland illegally. That allowed drivers and the company to avoid hefty fines.

A video from The Oregonian/OregonLive at the time showed the software in action, as regulators trying to hail an Uber were repeatedly denied service.

The company acknowledged having used the software in 2014, but said it stopped after an agreement cleared the way Uber and other ride-hailing apps to operate in Portland.

It offered some details on the use of the software, but city Commissioner Dan Saltzman, who oversees the Transportation Bureau, and Mayor Ted Wheeler said it wasn't sufficient. The City Council in May voted to subpoena the company for more information, including the company's Greyball "playbook" and the actual software behind the effort.

Saltzman said the company complied with the subpoena.

"Through this subpoena process, we have a greater understanding of their activities in Portland, and the extent to which the Greyball tool was used here," Saltzman said in a statement. "Moving forward, we have ensured that no attempts to evade regulators or deny service to riders in violation of City code or law will be allowed in the future."

Nonetheless, Saltzman said the City Council will consider new taxi-industry regulations later this year, including some aimed at preventing the use of software like Greyball.

-- Elliot Njus

enjus@oregonian.com

503-294-5034

@enjus