As the U.S. and eight other nations negotiate a wide-ranging trade agreement, several digital rights groups said they're concerned that the Trans-Pacific Partnership (TPP) will bring back controversial copyright-enforcement provisions pushed by some U.S. policymakers in recent years.

Negotiators for countries negotiating the TPP, also including Singapore, New Zealand, Australia and Chile, have not released their proposed agreement, but some digital rights groups are concerned that the U.S. will push for copyright enforcement provisions found in unsuccessful bills the U.S. Stop Online Piracy Act (SOPA) and the Protect IP Act (PIPA), and the still-alive Anti-Counterfeiting Trade Agreement (ACTA).

The TPP could hurt the freedom of individuals to access and use the Internet, critics said this week.

"We see that many of the intellectual-property provisions that have been reflected in ACTA, SOPA and PIPA are being pushed forward in this agreement," Maira Sutton, international IP coordinator at the Electronic Frontier Foundation, said in a briefing for reporters this week.

The EFF and other digital rights groups have several concerns about the trade agreement. TPP negotiations, started in 2007, entered a 14th round Thursday. Negotiators are meeting in Leesburg, Virginia, until Sept. 15. In addition to the nine countries now involved, negotiators have invited Canada and Mexico to join. Eventually, up to 21 countries, representing about 40 percent of the world's population, could be involved in the talks.

Working off a leaked version of the TPP from 2011, digital rights groups are concerned that the agreement doesn't balance copyright protections with exceptions, including fair use, said Rashmi Rangnath, director of the Global Knowledge Initiative at Public Knowledge.

In July, the Office of U.S. Trade Representative (USTR) proposed that the TPP include a process for creating "an appropriate balance in their copyright systems in providing copyright exceptions and limitations for purposes such as criticism, comment, news reporting, teaching, scholarship, and research."

But that process is "open to interpretation" and doesn't give countries enough guidance on how to create fair-use rights, Rangnath said. Instead, fair use should be spelled out in the trade agreement, she added.

Public Knowledge is also concerned about tough rules against breaking digital rights management (DRM).

A spokeswoman for the USTR defended the TPP negotiations, saying critics may be working off old copies of the proposed agreement. Copyright provisions were discussed extensively at the last negotiating round, in July, she said.

She also discounted concerns that TPP negotiators are not being transparent. The negotiating countries have encouraged outside participation in their meeting and have sought public comment on the trade deal, she noted.

"In the Trans-Pacific Partnership, USTR has endeavored to ensure that all voices are heard in the attempt to find the correct balance of views on complicated and complex trade issues," the agency said in a June statement. "To ensure public input on TPP from the start, USTR solicited written comments from interested individuals, organizations, and businesses before entering into the talks."

The agency has also "sought advice before negotiations began -- and continues to do so as they progress -- from scores of individual advisors" who serve on trade advisory committees in President Barack Obama's administration, the agency said.

Still, critics said they are concerned that the TPP will go beyond tough copyright-enforcement provisions found in ACTA and the U.S. Digital Millennium Copyright Act (DMCA).

The leaked copy of the TPP may require Internet service providers to cut off customers who are accused of repeated copyright infringement, said Carolina Rossini, EFF's director for international intellectual property. That type of rule would create a "private enforcement" regime beyond many countries' current laws, she said.

The treaty could also call for a DMCA-style takedown process for websites hosting user content. Some countries have "better due process" where users can challenge complaints from copyright holders, she said.

Grant Gross covers technology and telecom policy in the U.S. government for The IDG News Service. Follow Grant on Twitter at GrantGross. Grant's e-mail address is grant_gross@idg.com.