Americans and Germans are broadly supportive of a US-EU free-trade pact under negotiation, but differ over details, especially forging similar goods and services standards, according to a survey released Wednesday.

Common regulatory standards are perhaps the most ambitious objective of the bilateral talks that began last July to create the world's biggest free-trade zone.

The so-called Transatlantic Trade and Investment Partnership (TTIP) would vastly expand the US-EU economic relationship, already the world's largest, through a multipronged approach that includes tariff cuts and improved market access.

But hopes to conclude a deal by the end of 2014 have faded as talks bogged down, particularly over agricultural, food and environmental issues, with the US and EU at odds over regulations to protect people and the environment.

The Pew Research Center, in partnership with the Bertelsmann Foundation, the North American arm of the Germany-based private non-profit foundation , took a look at how residents of the world's largest economy and Europe's main powerhouse view the prospect of the new pact.

In 2013, the US was Germany's fourth biggest export market and source of imports. And Germany was the fifth-largest trading partner of the United States. US-EU trade totaled $649 billion, according to US government data.

The survey found that roughly the same number, 53 percent of Americans, and 55 percent of Germans, think that TTIP will be a "good thing" for their country.

But the respondents diverged over details of what would be the most economically significant regional free-trade agreement in history, especially disagreeing on harmonizing regulatory standards.

While 76 percent of the Americans surveyed supported making American and European standards for products and services similar, only 45 percent of Germans felt that way.

"On a range of consumer issues, Germans simply trust European regulatory norms more than American ones," the Pew report said. Americans, on the other hand, were supportive of US standards but not as strongly.

The longstanding US-EU dispute over the safety of genetically modified organisms used in US crops, including soybeans and corn, and US poultry and meat, stood out clearly in the survey findings.

More than nine in 10 Germans (94 percent) said they trusted EU food-safety standards and only 2.0 percent trusted US regulations, the survey found.

A tepid two in three Americans (67 percent) trusted US food-safety standards and 22 percent of Americans trusted European standards.

Similar lopsided trust was found in auto and environmental safety standards on both sides of the Atlantic.

- Data privacy -

Standards for data privacy, a sensitive issue exacerbated by the revelations of US National Security Agency spying, including listening in on phone calls made by German Chancellor Angela Merkel, stirred widely divergent views.

A large majority -- 85 percent -- of Germans trust European rather than US data privacy standards.

And not quite half of Americans -- 49 percent -- trusted the US standards, while 23 percent did not trust either the US or EU standards or had no opinion.

Another main finding of the surveys was a difference in motivations for backing the deal: China.

Americans were somewhat more in favor of the deal as part of a desire to boost competitiveness with the United States's second-biggest trading partner.

Forty-three percent of Americans said that was the most important reason TTIP is good for their country, compared with 32 percent of Germans.

A strong majority of Germans -- 63 percent -- said that more trade with China would be beneficial to their country, while only 51 percent of Americans held a similar view.

Pew Research noted that the differences in sentiment may reflect the fact that the US trade deficit with China was 36 times greater than Germany's imbalance with China in 2013.

The data was compiled from national telephone surveys in the US and Germany. In the US, 1,002 adults were surveyed from February 27 to March 2. In Germany, 953 were polled on February 25-26.

The margin of sampling error for the survey was 4.2 percentage points.