WASHINGTON, Aug 5 (Reuters) - The Trump administration will

announce as soon as Thursday a 15% tariff and a series of price

floors on products made from polysilicon, the key raw material

used in solar panels and semiconductors, according to four

sources familiar with the matter.

The move aims to protect U.S. polysilicon factories ‌from

growing Chinese ambitions in the chip supply chain.

The proclamation by U.S. President Donald Trump is expected

to include minimum import prices on polysilicon, wafers, cells

and modules, or solar panels, and a 15% tariff on the

polysilicon derivatives, the four sources said.

The administration's plan to pursue a hybrid system

combining a minimum import price with tariffs was first reported

by Reuters.

Trump's year-long national security investigation into

polysilicon by the Commerce Department also has major

implications for the growing domestic solar manufacturing

industry at a time when the U.S. leader has rolled back federal

support for renewable energy.

The Commerce Department and the White House did not

immediately respond to requests for comment.