China stocks closed flat on Friday with investor sentiment broadly subdued with market focus on Sino-U.S. tensions and despite a rally by semiconductor shares following U.S.-based Nvidia's share price surge overnight.

** China's blue-chip CSI300 Index closed flat, while the Shanghai Composite Index edged up 0.4%.

** Hong Kong market was closed on Friday for public holiday.

** For the week, CSI300 Index and Hong Kong's benchmark Hang Seng Index were down 2.4% and 3.6%, respectively, both marking the worst weekly performance in 10 weeks.

** The U.S. State Department warned on Thursday that China was capable of launching cyber attacks against critical infrastructure, including oil and gas pipelines and rail systems, after researchers discovered a Chinese hacking group had been spying on such networks.

** Meanwhile, U.S. Commerce Secretary Gina Raimondo and Chinese Commerce Minister Wang Wentao traded barbs on trade, investment and export policies in talks on Thursday described by Raimondo's office as "candid and substantive."

** Sector performances were mixed with chipmakers outperforming other sectors. Shares of Chinese chipmakers jumped after a 24% overnight surge in U.S.-based Nvidia Corp fuelled Chinese interest in the sector.

** The STAR Chip Index was up 2.9%, logging its best day in nearly a month.

** Zbit Semiconductor Inc surged 20%, reaching a record high.

** New energy shares slumped 2.2%, continuing the downward trend.

** Automobile companies BYD Co Ltd and Great Wall Motor Co Ltd were down 3.4% and 4.3%, respectively. Great Wall Motor said on Thursday its rival BYD failed on hybrid emissions.

(Reporting by Shanghai Newsroom; editing by Sherry Jacob-Phillips and Jason Neely)