The Justice Department, in a dramatic and unexpected court brief, has told a federal judge that the makers of the herbicide Agent Orange should bear sole liability for any health problems their product may have caused Vietnam veterans.

In strong language, the brief rejects the seven chemical companies' claims that they should not be held liable because they were following government orders to make Agent Orange -- an argument commonly called the "government contractor" defense.

"Profit, not compulsion or patriotism," was the companies' primary motive in producing Agent Orange, the government said.

The government offers a number of exhibits to disprove the companies' claims that they were under "compulsion to manufacture" Agent Orange and that it was a "product invented by the government."

The National Law Journal, in an article to be published Monday, said some of the documents in the brief, sealed from the public, show the companies hiding information from the government about the health hazards of Agent Orange.

The legal affairs journal, which said it had seen some of the documents, also reported that the companies discussed ways to prevent the government from taking over the manufacture of Agent Orange.

Garry Hamlin, a spokesman for Dow Chemical Co., the largest manufacturer of Agent Orange, said yesterday that the company strongly disagrees with the government's brief. He said that military officials were aware in the 1950s of possible health hazards of Agent Orange, but he said the "government contractor" defense, in effect, was moot because "the overwhelming scientific evidence shows Agent Orange didn't harm anyone's health."

The brief says the government does not consider itself liable for possible damages caused by Agent Orange, which was widely used to clear jungle and kill crops.

In May, attorneys for several thousand Vietnam veterans signed a $180 million out-of-court settlement in a class-action suit against the seven manufacturers. The veterans claimed that exposure to dioxin, a toxic contaminant in Agent Orange, had caused them numerous health problems, including cancer and birth defects in their offspring.

Judge Jack B. Weinstein of U.S. District Court in New York City, who helped forge the out-of-court settlement and has been holding hearings to determine whether he should approve it, has hinted several times that the government should voluntarily contribute to the $180 million fund.

One of the reasons veterans' attorneys cited in agreeing to the settlement was fear that the court might agree that the companies were shielded by the "government contractor" defense. Until this week, the government had not indicated that it would take such a hard stand against that argument.

Veterans who are part of the settlement cannot sue the companies, but about 4,000 veterans have opted out of the settlement and are suing the companies independently. The government brief is expected to make it more difficult for the companies to protect themselves from these suits.

The brief also shows that the government will fight any Agent Orange suits filed against it by chemical companies or by veterans' families. Veterans are forbidden to sue the government under a long-standing doctrine that prohibits soldiers from claiming damages because of war injuries.

The government filed the brief in answer to a request for a summary judgment filed by the companies, which claimed that all suits filed against them by veterans who had opted out of the settlement should be dismissed, in part because of the "government contractor" defense.

The companies also claimed that scientific evidence shows that small amounts of dioxin are not dangerous to humans and, even if dioxin is dangerous, there is no way veterans could prove which company's product damaged their health -- a standard requirement in product liability suits. The judge has not ruled on those claims.

These companies manufactured Agent Orange: Hercules Inc., Dow Chemical Co., Monsanto Co., Diamond Shamrock Corp., Uniroyal Inc., T.H. Agriculture & Nutrition Co. and Thompson Chemical Co.