Hanoi - Vietnam plans to take legal action to prevent Canada from imposing anti-dumping duties on Vietnamese waterproof shoes, a government official said Thursday.

The Canadian government made a preliminary determination May 28 that Vietnamese manufacturers were dumping rubber and plastic waterproof footwear in the Canadian market. The determination could trigger heavy anti-dumping tariffs.

"This is a trade measure, so we have to follow the normal procedures," said Nguyen Duc Thanh, deputy director of the Vietnam Competition Administration Department. "Where there is a legal action, there will be a counteraction."

Thanh said his department would have a response ready by August 28 when Canadian inspectors must complete a follow-up investigation.

Phan Thi My Hien, general secretary of the Vietnam Leather and Footwear Association, said the Canadians planned to investigate four Vietnamese companies for dumping: Vinh Long Footwear Co, Pou Yuen Co, Fulgent Sun Footwear and Stateway Vietnam.

If the companies cooperate with the investigation, they risk a maximum tariff rate of 16 per cent if the Canadians find against them, according to a report Wednesday on Voice of Vietnam radio. Companies that do not cooperate may be hit with tariffs of 49 per cent.

Canada is also investigating Chinese waterproof footwear manufacturers. They face possible tariff rates of 21.7 to 52.3 per cent.