BRUSSELS—Chinese solar-panel manufacturers will face import tariffs of up to 67.9% at European Union borders under a plan from the 27-nation bloc's executive body, according to a copy of the plan viewed by The Wall Street Journal.

The tariffs, which will come into effect by June 6, will range from 37.3% to 67.9%, according to the document, drafted by the European Commission. Some of the largest Chinese manufacturers will face duties on the higher end of that range.

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