By Helen Reid

LONDON (Reuters) -Danish jewellery maker Pandora cut its annual profit margin guidance on Tuesday due to a decline in the U.S. dollar and said it is preparing for scenarios related to U.S. tariffs that could add tens of millions of dollars to its costs.

Pandora, whose biggest market is the U.S., said it now expected a margin on earnings before interest and tax (EBIT) of around 24% this year, having previously targeted around 24.5%. It stuck to its guidance of 7-8% organic growth for the year.

The charm bracelet maker is among the European companies most at risk from the possibility U.S. President Donald Trump reinstates steep so-called "reciprocal" tariffs, including a 37% tariff on Thailand where its two factories are located.

These tariffs were implemented, then paused for 90 days to allow for negotiations. A 10% blanket tariff on imports from all countries remains in place.

Pandora said that, if the current level of tariffs remains in place, there would be a cost impact of 250 million Danish crowns ($38.00 million) this year and 300 million Danish crowns annually thereafter.

If the 37% tariff on Thailand resumes, Pandora expects an impact of 500 million Danish crowns this year, and 900 million Danish crowns annually thereafter.

That is lower than Pandora's April forecast of 1.2 billion Danish crowns annually, as the company said it expects to be able to ship products directly from Thailand to Canada and Latin America by early 2026. It currently uses a warehouse in Baltimore to serve North and South America.

"In both scenarios, Pandora will consider further price increases," the company said, the latest in a string of brands and retailers to warn of higher U.S. prices for their goods.

Pandora has already hiked prices across the board by 4% in April, following a 5% increase in October last year, in response to the rising cost of silver, a key material for its jewellery.

The company's first-quarter revenue matched analysts' expectations, and it said it would continue to invest in marketing while acknowledging an "uncertain" economic backdrop.

Revenue for the first quarter was 7.347 billion Danish crowns ($1.12 billion), slightly above analysts' median forecast of 7.310 billion, while Pandora delivered organic growth of 7%.

"We are pleased with how we've started the year, especially given the very high volatility in the world around us," its CEO Alexander Lacik said in a statement.

A weaker dollar hurts Pandora's revenues as sales in dollars are worth less when converted into Danish crowns.

($1 = 6.5802 Danish crowns)

(Reporting by Helen Reid in London and Isabelle Yr Carlsson in Copenhagen; Editing by Jan Harvey and Tomasz Janowski)