WASHINGTON  The United Steelworkers and two Chinese companies announced Friday that they had signed an agreement assuring that major components of machines for a $1.5 billion wind farm in Texas would be made in the United States.

The deal potentially defuses a conflict over American stimulus dollars being used to subsidize foreign companies.

Without releasing full details, the union said that the steel for the wind towers, enclosures for working parts atop the towers and reinforcing bars for the bases would be sourced in the United States. So will the blades, which are not made of steel but are often made by steelworkers, the union and the two companies said.

The agreement was brokered with the Shenyang Power Group, known as SPG, and a subsidiary that it partly owns, A-Power Energy Generation Systems, which have entered a joint venture with the American investment firm U.S. Renewable Energy Group to build the wind farm in West Texas.