Managers of Sleep Quarters at Clark's Pond in South Portland, relax on one of their Tempur-Pedic beds.

The United States is investigating alleged dumping of China-made mattresses after complaints from several U.S. manufacturers, including Leggett & Platt, Tempur Sealy, and others, the Department of Commerce said on Friday.

Shares of Tempur Sealy were up nearly 1.5 percent in late morning trade following the Commerce statement, while shares of Leggett & Platt up less than 1 percent.

Other privately held companies - Corsicana Mattress Co, Elite Comfort Solutions, Future Foam Inc, FXI Inc, Innocor Inc, Kolcraft Enterprises Inc and Serta Simmons Bedding LLC - also signed the petition asking Commerce to investigate, the department said.

Mattresses from China were estimated to be worth about $436.5 million in 2017, according to the department.

It said the U.S. International Trade Commission (ITC) would make its initial decision by Nov. 2, followed by the Commerce Department by Feb. 27.

A final decision is scheduled for May 13, but could be later, it added.

If the department determines that China is selling mattresses in the United States at less than fair value, and is harming U.S. sellers, it would then impose duties, it said in its statement.