Stronger Rear-Door Latches Ordered : Autos: Agency says move should prevent about a dozen deaths a year. Car makers disputed need for upgrade.

The federal government on Wednesday ordered stronger locks and hinges for the back doors of hatchbacks, vans, station wagons and sport-utility vehicles.

Regulators said at least 40 deaths have occurred in incidents in which passengers fell out of rear doors.

The National Highway Traffic Safety Administration said the new regulation requires that rear doors meet the same standard that now applies to vehicle side doors. It said the action should prevent about 13 deaths a year.

The rule takes effect Sept. 1, 1997.

Ricardo Martinez, head of the NHTSA, said that “with the increasing popularity of minivans and sport-utility vehicles, fatalities and back-door ejections are also increasing.

“Stronger latches, hinges and locks are expected to prevent about 13 fatalities each year,” he said. “Even more lives could be saved if everyone used seat belts. A stronger latch is not a substitute for belt use.”

New latches are expected to cost about $3 per vehicle.

“It’s past due,” said Ralph Hoar, an Arlington, Va., consultant who assists lawyers in automotive lawsuits. “I’m not sure it would have happened if the agency hadn’t been caught with its pants down in the Chrysler investigation.”

The NHTSA launched an investigation into failures of rear-door latches on Chrysler Corp.’s best-selling minivans, the Plymouth Voyager, Dodge Caravan and Chrysler Town and Country.

In March, Chrysler announced it would replace the latches on more than 4.5 million minivans. But so far, only about 60,000 owners have been mailed recall notices.

Chrysler, Ford Motor Co., General Motors Corp. and other manufacturers had resisted efforts by the Institute for Insurance Safety and others to improve the locks on minivans and sport-utility vehicles, which have won an increasingly large share of the automotive market over the past decade. The manufacturers said stronger latches were unnecessary.

Hoar said that while other manufacturers use double locks on their rear doors, Chrysler uses a single lock.

“It is a mystery to me why manufacturers 10 years ago started marketing vans as family passenger vehicles that did not meet the same standard as passenger cars,” he said.

General Motors said it believes that many of its vehicles already meet the new guideline and the rest of its vehicles will do so by the government’s deadline.

“We will meet the regulation by the time it takes effect,” said Ed Lechtzin, a GM spokesman.

Chrysler and Ford had no immediate comment.