Raytheon Co. has disclosed it is accelerating around-the-clock manufacture of its successful Patriot anti-missile system at the U.S. Army's request.

The company said Tuesday it had added production workers and speeded up the 24-hour-a-day output of the missile system in August, shortly after the invasion of Kuwait. But it withheld news of the production rise because of fear of compromising U.S. forces during the military buildup in the Persian Gulf, a company spokesman said.The Patriot has since proved to be a highly effective shield for U.S. forces in Saudi Arabia when they have come under attack from Soviet-made Scud ballistic missiles fired by Iraq.

The Patriot had been untested in combat until the gulf war.