The finding was mentioned in the public version of an annual report to Congress by the Committee on Foreign Investment in the United States, an interagency body that reviews foreign investment for potential national security concerns.

One investment now before the committee is Chinese state-owned CNOOC's purchase of Canadian energy producer Nexen Inc. Ottawa has approved the deal, but CFIUS is reviewing whether to allow CNOOC to acquire Nexen's oilfields in the Gulf of Mexico.

The report, issued on Thursday, said the U.S. intelligence community "judges with moderate confidence that there is likely a coordinated strategy among one or more foreign governments or companies to acquire U.S. companies involved in research, development, or production of critical technologies for which the United States is a leading producer."

The public version did not identify any particular country but said information supporting the intelligence community's assessment was provided in the classified version of the report that was sent to Congress.

U.S. government officials have publicly complained about Chinese government policies that pressure American companies to transfer valuable technologies to do business in China.

That issue was on the agenda for high-level U.S.-China talks this week in Washington, with the United States welcoming a new Chinese pledge not to make technology transfer a condition for market access.

The U.S. business community has also complained about growing theft of U.S. trade secrets by Chinese companies, often by means of sophisticated cyberattacks.

The United States and China also agreed this week to hold technical talks next year on cybersecurity.

Last month, the U.S.-China Economic and Security Review Commission urged Congress to conduct an in-depth assessment of Chinese cyberspying and consider imposing tougher penalties on companies that benefit from industrial espionage.

The advisory panel, created by the U.S. Congress, also urged tougher U.S. scrutiny of all Chinese investment by state-owned enterprises.

"China is engaged in a state-directed coordinated strategy to acquire critical U.S. assets important to our economic and national security," commission member Michael Wessel told Reuters on Friday, saying he was reflecting his own views.

"Just in the last few weeks, we have seen an accelerated buying spree by Chinese companies with ties to the state," Wessel said, referring to a bid by BGI-Shenzhen to buy U.S. life sciences company Complete Genomics and investments made by Chinese petroleum company Sinopec in Wyoming.

(Reporting By Doug Palmer; Editing by Neil Stempleman)

Stocks treated in this article : CNOOC Limited, Complete Genomics, Inc., Nexen Inc.