WASHINGTON (Reuters) - The U.S. Trade Representative's Office will hold a hearing on Tuesday into older Chinese-made "legacy" semiconductors that could heap more U.S. tariffs on chips from China that power everyday goods from autos to washing machines to telecoms gear.

The probe, which was started under President Joe Biden in December, aims to protect American and other semiconductor producers from China's massive state-driven buildup of domestic chip supply. A 50% U.S. tariff on Chinese semiconductors started on Jan. 1.