Mayor Marion Barry announced yesterday that he has signed a D.C. Council bill that holds assault-weapon merchants liable for injuries or deaths that the guns cause in the District.

The legislation, the first of its kind in the country, is expected to encounter resistance in Congress, which recently quashed other strict gun-control measures amid pressure from the National Rifle Association.

NRA officials said yesterday they intend to fight the District's gun-liability measure when it arrives for review on Capitol Hill. Richard Gardiner, the NRA's director of state and local affairs, ridiculed the bill as a "perverted" and unconstitutional act that would not survive court scrutiny.

"It's going to die in court," Gardiner said. "It's offensive that the council could conceive of holding an innocent person, the manufacturer, responsible for the actions of a criminal."

Barry, who leaves office in two weeks, said yesterday that he signed the bill late Monday because it may help reduce the flow of guns and the violent crime rate in the city.

"The manufacturer has to begin to take some of the weight," Barry said. "We don't need those guns on the streets."

Gun-control advocates applauded Barry for signing the bill and said they hope that it inspires other cities to craft similar policies.

"We're very pleased with the mayor's decision; now we'll start focusing our attention on Capitol Hill," said Jeff Muchnick, legislative director of the Coalition to Stop Gun Violence. "There's a lot of work to do to make sure it gets through. It's going to be tough."

The gun-liability legislation covers a variety of assault weapons, including semiautomatic guns such as the Uzi, the Beretta and the Tec-9. The legislation allows shooting victims or their families to recover damages from the manufacturers or retailers of those weapons.

Council members said they approved the measure to curb the record amount of violence in the District.

A total of 467 people have been slain in the city this year. The council's last strict gun-control legislation, passed in 1976, banned the sale of weapons in the city, but the flow of guns remains high.

In the last two years, D.C. police have confiscated more than 8,000 guns, nearly 70 percent of which were traced to retailers in Maryland and Virginia.

Council members said they hoped to make those retailers, who have reacted with outrage to the new legislation, think twice before selling assault weapons. Although there are early signs in the House that the gun-liability legislation will face strong opposition, the council has said it tailored the measure to win congressional support.

First, it dropped a plan to make all handgun manufacturers liable for shootings and shooting deaths in the District. And the list of assault weapons covered by the D.C. legislation is identical to the list of assault weapons that the Senate voted to ban last year -- but which the House rejected.

"Since it's the same weapons the Senate ageed to ban, we don't think it should be considered too far of a step," Muchnick said.

If the legislation survives a congressional review, it is still not clear how it would be viewed in court because there have been few cases on the issue.

The Maryland Court of Appeals upheld a suit against a manufacturer of inexpensive handguns in 1985. However, last year the D.C. Court of Appeals dismissed a similar suit by saying that a gun sale was "not dangerous in and of itself, but rather the result of actions taken by a third party."