WASHINGTON  The Energy Department is subsidizing two Russian nuclear institutes that are building important parts of a reactor in Iran whose construction the United States spent years trying to stop, according to a House committee.

The institutes, both in Nizhny Novgorod, gave American officials copies of sales presentations that listed the Bushehr reactor, which Russia has agreed to fuel, as one of their projects. One institute is providing control systems, including control room equipment, and the other, hundreds of pumps and ventilation fans.

The Energy Department is subsidizing the institutes under the Initiatives for Proliferation Prevention, a program set up in 1994, after the collapse of the Soviet Union. The program was intended to prevent newly impoverished scientists and their institutions from selling expertise to states or terrorist groups that want nuclear weapons.

The United States supplements the salaries of scientists and pays overhead at those institutes, according to the House Oversight and Investigations subcommittee.