Airbus parent EADS and German steelmaker ThyssenKrupp recorded major attacks by Chinese hackers in 2012, German magazine Der Spiegel reported, citing unidentified people within the two companies.
That is a trend seen throughout the German economy, where companies are increasingly being attacked by Chinese hackers, the magazine said, citing information from the German government.
A spokesman for EADS told Reuters the attacks were "standard attacks" and the company was working closely with government authorities on the issue of cyber security.
ThyssenKrupp also confirmed an attack, saying it took place in the United States from a Chinese internet address and that it had no information as to what data the attackers obtained, according to Der Spiegel.
ThyssenKrupp was not immediately available for comment when tried by Reuters. The Chinese embassy in Berlin and the German economy ministry were also not immediately available to comment.
When confronted with similar accusations in the past, China's Defence Ministry has issued a flat denial and said hacking is a global problem and that China is one of world's biggest victims of cyber assaults.
Germany's Federal Office for the Protection of the Constitution recorded almost 1,100 digital attacks from foreign secret services in 2012, mostly targeted on politicians involved with energy and finance, Der Spiegel said.
Chinese hackers tend to take aim at the largest corporations and most innovative technology companies, using trick emails that appear to come from trusted colleagues but bear attachments tainted with viruses, spyware and other malicious software, according to Western cyber investigators.
(Reporting by Peter Dinkloh, Tim Hepher and Alexandra Hudson; Editing by Mark Potter)