German car giants Daimler and Volkswagen will ink multi-billion-dollar contracts with Chinese partners Friday during a visit by a top Chinese official, a government source in Berlin said.

"The contracts with Daimler and VW will be more than five billion dollars," the source told AFP on Thursday.

Germany's foreign ministry had said earlier that contracts would be signed after a meeting between Chinese Vice Premier Li Keqiang and Deputy Chancellor Guido Westerwelle, without giving more details.

Westerwelle, also foreign minister, and Li would discuss "the further development of economic and political ties as well as the continuation of reforms in China and cultural cooperation," the ministry said.

Li, widely tipped to be the next premier, arrived in Berlin earlier Thursday and was set to hold talks with Chancellor Angela Merkel on Friday.

Later Thursday, he met Economy Minister Rainer Bruederle who raised the issue of market access in China for German firms, technology transfer and raw material supplies.

"Technology transfer offers both sides great opportunities when it takes place willingly and under fair terms," Bruederle said in a ministry statement.

"I am convinced that everyone will benefit if China ensures open, free and orderly access to its raw materials," he said.

He noted that "given the scope for improvement on market access (in China), it is encouraging that Li announced a greater opening up of the service sector."

Earlier Thursday before the talks, Bruederle had slammed conditions for Western firms operating in China in an interview with business daily Handelsblatt.

"Improvements need to be made when it comes to access for German firms on the Chinese market," Bruederle said, citing in particular the insurance and banking sectors.

He praised the Chinese authorities however for "taking our concerns seriously and seeking to improve the investment environment for foreign companies."

Following his trip to Berlin, Li was due in London.

He has already visited Madrid where he said Beijing was willing to buy around six billion euros worth of Spanish debt, daily El Pais quoted government sources as saying.

After eurozone members Greece and Ireland were forced to seek bailouts worth tens of billions of euros last year, Spain, together with Portugal, have been seen as next in line in the 17-country currency union to need help.

China and Germany are the number one and number two exporters in the world respectively.

According to Berlin's statistics, Germany exported 37.3 billion euros (48.7 billion dollars) worth of goods to China in 2009, with Chinese exports to Germany worth 56.7 billion euros.

For the 10 months to October 2010, German exports to China soared 45 percent, with Chinese shipments to Germany up 34 percent, Bruederle said.