Europe has no interest in a bilateral investment pact with China that omits measures to prise open the Asian giant's markets, the European Union's trade commissioner said, after a summit with Chinese leaders announced plans for treaty talks.

China and the EU have said the landmark treaty aims to boost investment that lags growing trade and address market access, long a point of contention for foreign firms operating in China, which say they are barred from key sectors often reserved for state-owned enterprises.

"I believe we have no interest in making an investment agreement that is limited to investment protection only," EU Trade Commissioner Karel De Gucht told reporters in Beijing.

"An agreement only makes sense if it is also about market opening," De Gucht said, noting that Chinese leaders had agreed only to discuss the issue. "It will certainly not be an easy negotiation."

EU officials say talks on the pact, a widely expected outcome of the summit, will be a test of China's willingness to compromise and play by rules set by the World Trade Organization.

De Gucht said he expected talks would begin within a matter of weeks, but would not estimate how long a deal would take.

"It depends, I believe, also on where <China's> economy is going in the coming years," he said.

"From that it will depend on which sectors they are ready to open for investment. To put a date on that is pure speculation."

Experts expect that reaching a deal will take several years if talks go smoothly. The United States has been in talks with China on a bilateral investment treaty off and on since 2008.

Europe is China's most important trading partner and for the EU, China is second only to the United States. But two-way ties have been weighed down by a series of trade rows over everything from steel and solar panels to wine.

In 2012, two-way trade in goods and services reached 483.5 billion euros, the EU delegation to China says. China's exports to Europe last year were worth 289.7 billion euros, while Europe's exports to China amounted to 143.9 billion.

However, EU imports from China last year fell for the first time since the financial crisis, falling 0.9 percent.

State media said China aims to boost two-way trade with the EU to $1 trillion by 2020, nearly doubling 2012 levels.

De Gucht said that figure seemed high, adding that the EU's trade relationship with China had to be kept in context.

"We should just treat them as any other trading partner-a big one, yes. Not the biggest one. We should be cool with respect to the Chinese," he said.