COPENHAGEN (Reuters) -European wind shares fell on Tuesday after U.S. President Donald Trump axed support for new U.S. offshore wind power on his first day in office, with top decliner Orsted further straining under the weight of impairments on its U.S. ventures.

Orsted lost as much as 17% after it reported 12.1 billion Danish crowns ($1.69 billion) in impairment charges related to the U.S. offshore market.

A delay and higher costs for Orsted's Sunrise Wind project, which is expected to be the largest U.S. offshore wind farm once it is completed, were the main reason for the plunge, analysts said.

But the company also flagged impairments on seabed leases which could be directly linked to Trump, Sydbank analyst Jacob Pedersen told Reuters.

"Orsted now has some assets in the U.S. that are worthless. If there is nothing to be built because of Trump, Orsted can neither sell nor use the leases," he said.

U.S. President Donald Trump on Monday suspended new federal offshore wind leasing pending an environmental and economic review, saying wind mills are ugly, expensive and harm wildlife.

Orsted and other companies have struggled to unleash the potential of the U.S. offshore wind market and the industry's outlook has been further complicated by Trump's vows to scrap offshore wind projects as one of his first acts.

Italy's Prysmian will abandon a plan to build a plant in the United States to make cables for offshore wind parks, the group said in a statement seen by Reuters on Tuesday.

Prysmian, the world's biggest cable maker and a major player in offshore wind transmission, does not see a strong enough market in the U.S. for offshore wind farms, and says its transmission business backlog of 18 billion euros is entirely concentrated in Europe with no U.S. exposure.

Prysmian's project, announced in 2021, involved an investment of around 200 million euros ($207 million) in Somerset, Massachusetts, as part of two preliminary contracts worth a total of almost $900 million in the U.S., which never materialised.

Shares in Prysmian, which closed at an all-time high on Monday, fell 1.5% by 1208 GMT while Orsted shares, which have plunged some 84% since peaking in 2021, traded down 13.6%.

"We see higher risks for the U.S. offshore wind industry given President Trump's policies against the industry, including the risk of no further U.S. offshore wind development over the medium term," Barclays analysts wrote in a research note. The U.S. renewables market is a key growth sector for several European utility companies, including Orsted, Portugal's EDP Renovaveis and Germany's top power producer RWE, which traded 2% and 1% lower, respectively.

Shares in wind turbine makers Nordex and Vestas fell around 2%.