SHANGHAI — Beijing and Washington have threatened each other with tariffs for weeks, raising the prospect of a trade war. But on Tuesday, China took a step to lower tensions, offering to make it easier for foreign automakers and aerospace manufacturers to own factories in the country.

The Chinese authorities said that in the next five years they would ease rules that have long required carmakers like General Motors, Toyota and Volkswagen to link up with a local partner before building a factory in China. For manufacturers of electric cars, as well as for companies that make jetliners, helicopters and drones, Beijing plans to move even faster, eliminating foreign ownership limits this year.

Opening up the electric-car sector is a potential boon for Tesla Motors, which has already identified a site in Shanghai for a factory but has not wanted a partner for fear of losing control of its technology. Big automakers, especially Volkswagen, have also been preparing to set up large electric-vehicle subsidiaries in China as Beijing has made clear that it will use a mix of subsidies and penalties to shift the market sharply toward more electric cars.

Loosening limits for electric carmakers and aerospace manufacturers is notable because those are two areas where Beijing and Washington have been increasingly at loggerheads. The sectors are among 10 industries in Beijing’s Made in China 2025 plan, which calls for extensive government support to expand China’s production and self-sufficiency in everything from microchips to robotics.