By Shanima A

Nov 27 (Reuters) - Britain's Johnson Matthey ( JMPLF ) said on Wednesday

the United States' proposed tariff changes to imports from Mexico would impact

its total sales by up to 6% and that it was confident about its North American

manufacturing footprint.

U.S. President-elect Donald Trump on Monday pledged to impose a 25% tariff

on imports from Canada and Mexico till such time that they clamp down on drugs,

particularly fentanyl, and migrants crossing the border.

"We have no specific plans changed right now, but of course we'll have to

monitor what happens overall with the new administration in the U.S., the impact

that it has on global trade and relative trade flows," CEO Liam Condon told

Reuters.

The group "typically" services U.S. market from its U.S. business, so it is

"less concerned" about tariffs, he said.

The centuries-old British company, which has its roots in testing precious

metals for purity, missed analysts' expectations for first-half revenue and

underlying profit on Wednesday amid a decline in global vehicle production and a

subdued Platinum Group Metals trading business.

Shares of the company fell as much as 7.2% to a more than 15-year low of

1,386 pence after the results.

Johnson Matthey ( JMPLF ), which manufactures catalytic converters and pollution

filters for cars, maintained its outlook for the full-year however, helped by

the progress in its cost-cutting efforts and expectations of an improved second

half.

Condon also said the impact of the increase in UK employers' National

Insurance Contributions on the group would be in about the mid-single digit

millions.