The Bush administration is tightening export controls as it moves to change a system that allowed U.S. companies to ship potentially dangerous technology to Iraq.

The administration on Thursday issued regulations expanding export controls on materials that could be used to produce deadly chemical and biological weapons and missile delivery systems.The measures are designed to plug holes in the existing controls and government review process that allowed the Commerce Department to approve $1.5 billion in dual-use exports to Iraq in recent years.

Baghdad was able to use the advanced U.S. technology in its chemical and biological weapons production, but the exports were permitted to help Iraq in its war with Iran.

Now the Commerce Department is getting tough and threatening to put companies out of business if they violate the new regulations.

U.S. officials plan to consult soon with allied countries to try to persuade them to adopt the same curbs, and they hope to include China and the Soviet Union in the process, one administration official said.

Business executives contend the new regulations are too broad and will cost U.S. industry billions of dollars in lost exports of chemicals and other products.

The regulations establish a list of dual-use equipment that has legitimate commercial uses but also potential application to chemical and biological weapons production.

Announcing the controls, the White House said Iraqi President "Saddam Hussein's use of chemical weapons against his own citizens, his use of Scud missiles to terrorize civilian populations, and the chilling specter of germ warfare and nuclear weapons have brought home the dangers proliferation poses to American interests and global peace and stability."

The new regulations implement an executive order that President Bush issued last November after he vetoed export restrictions passed by Congress.

A White House statement said the regulations were designed "to minimize interference with legitimate international trade."

The expanded controls apply to equipment, chemicals and even entire plants that can be used to makechemical or biological weapons.