China’s Three Gorges Corp. has bought a 21 percent share in Portugal’s largest power producer from the country’s debt-burdened government, in a clear sign that Beijing may help bail out cash-strapped European nations, but only if it gets something worthwhile in return.

The Chinese government has responded coolly to pleas that it use some of its $3.2 trillion in foreign reserves to buy bonds from struggling governments in Greece, Italy, and Spain. But officials here have said they are interested in picking up European assets.

This week’s $3.5 billion deal by Three Gorges, which operates the world's largest hydroelectric project, is the largest-ever Chinese investment in Europe. It comes only weeks after Trade Minister Chen Deming told Chinese businessmen that “some European countries are facing a debt crisis and hope to convert their assets into cash and would like foreign capital to acquire their enterprises. We will be watching closely and pushing forward progress.”

The Portuguese government had been forced to sell off its share in Energias de Portugal as part of a €78 billion bailout package from the European Union and the International Monetary Fund. Lisbon is also selling a 40 percent share in its national power grid operator, and another state-owned Chinese company, China State Grid Corp., is bidding for it.

“The European economy needs blood, but not in the form of a transfusion asking for us to buy their bonds,” said Wang Yiming, a senior economic policymaker, at a meeting in Brussels last month. “We need to create new blood by promoting investment.”

Not always welcome

Such investment is not always welcome. Last month the Icelandic government nixed a $200 million plan by a Chinese businessman to buy 115 square miles of land to build a tourist resort.

Chinese Deputy Foreign Minister Fu Ying lashed out earlier this month at such reticence, saying she hoped that “our economic activities are not interpreted from a political perspective and are not imbued with political interests.”

Beijing is encouraging its state-owned enterprises, many of which are flush with cash, to seek opportunities abroad, and Europe is a promising destination.

Britain, for example, is seeking foreign investors to fund the lion’s share of a $310 billion plan to upgrade the nation’s roads, railways, utilities, and Internet systems, and is looking to China, among others.

“We are looking for short-term projects to invest in almost immediately, and that could mean next year,” Qi Yue, an executive at CITIC Construction Co., told the official China Daily on his way to the first meeting of the UK-China Infrastructure Taskforce last week.

Chinese corporations are growing increasingly adventurous in Europe. The Shanghai-based automobile manufacturer Geely bought Volvo in 2010, and earlier this year the China National Chemical Corp. paid $2.2 billion for Elkem, the Norwegian manufacturer of key components in solar panels.

Still, China’s total non-financial investment in European Union member states is still tiny – around $15 billion according to a recent report by the Rhodium Group, a consultancy in New York, which is only 0.2 percent of all the foreign investment in Europe.