Carl Icahn sold about US$30 million of shares in crane manufacturer Manitowoc Co. in the weeks before President Trump said he would impose new tariffs on U.S. steel imports.

The billionaire investor sold more than a third of his stake in the Manitowoc, Wisconsin-based company, which has a sizable exposure to U.S. steel imports, from Feb. 12 through Feb. 22, according to a regulatory filing last Friday. Icahn remains Manitowoc’s fifth-largest holder with about 4.8 per cent of the company’s common shares.

President Donald Trump started an investigation to determine the effect of steel and aluminum trading on the U.S. last April, citing national security concerns. The U.S. Commerce Department delivered its recommendations for steel to the president on Jan. 11 and for aluminum on Jan. 22. Both were made public on Feb. 16.

On Thursday, Trump proposed slapping tariffs of 25 per cent on imported steel and 10 per cent on aluminum, though the plans are yet to be formalized.

Icahn didn’t immediately respond to requests for comment. The investor quit his role as a special regulatory adviser to Trump in August after Democratic lawmakers asked questions about potential conflicts of interest with his business dealings in oil refining and insurance. Icahn at the time denied profiting from his advice-giving role, a possibility raised by critics who had asked administration officials to investigate his work.

A spokesman for Manitowoc declined to comment.

Manitowoc’s suppliers include Belgium’s Bekaert SA, which makes wire products and steel cables, as well as South Korean construction-parts manufacturer Dongil Metal Co., according to data compiled by Bloomberg. It also sources equipment from U.S. industrial manufacturer Dana Inc., the data show.

The company, along with Terex Corp., Oshkosh Corp. and Hyster-Yale Materials Handling Inc., was downgraded to neutral from outperform by Baird analyst Mircea Dobre on Friday. Dobre said the tariffs are a “broad negative” for users of steel in the machinery industry.

Icahn disclosed a stake in Manitowoc in late 2014 and said at the time he may seek board representation at the company, calling its stock undervalued.

Shares of Manitowoc fell as much as 7 per cent in New York trading Friday. They’ve lost about 22 per cent since Feb. 9, the last trading day before Icahn starting reducing his stake.

--With assistance from Josh Wingrove and Thomas Black