wASHINGTON, Aug. 12 -- Nvidia and Advanced Micro Devices Inc have agreed to give the US government 15% of revenue from sales to China of advanced computer chips, a US official said, in an unusual move likely to faze American companies. US President Donald Trump's administration halted sales of H20 chips to China in April, but Nvidia announced last month Washington had said it would allow the company to resume sales and it hoped to start deliveries soon. Another US official has said that the commerce department had begun issuing licences for the sale of H20 artificial intelligence chips to China. The new levy could also hurt margins for the two companies, analysts warned. P11...