Activist investor Carl Icahn said on Wednesday he did not have any prior knowledge about President Donald Trump's plan to impose import tariffs on steel and aluminum before he reduced his stake in crane maker Manitowoc Co. Inc. last month.

Icahn called reports connecting his sale to the tariffs proposal "categorically untrue," and attributed the cut in stake to "legitimate investment reasons."

Last month, Icahn reduced his stake in Manitowoc to 4.85 percent from 7.81 percent, according to SEC filings.

About a week after that, Trump said he would impose 25 percent tariffs on steel imports and 10 percent on imported aluminum to make domestic production more attractive.

Shares of large steel and aluminum users in the United States tumbled following the announcement as it raised concerns about higher prices for raw materials which will force them to raise prices for consumers.

Manitowoc's shares were down 2.2 percent on Wednesday. Up to Tuesday's close, the stock lost 27.8 percent this year.