The Metropolitan Washington Council of Governments urged the District, Maryland and Virginia yesterday to pass legislation to help curb drunk driving and require use of seat belts in cars.

The recommendations, approved by the council's board of directors, included setting 21 as the minimum age for purchasing alcoholic beverages in the District and Virginia. In Maryland, the minimum age now is 21.

The council also recommended automatic suspension of drivers' licenses for drunk driving offenses and stiffer standards for determining whether a driver is intoxicated.

In urging the District, Maryland and Virginia to "mandate safety-belt use," the council cited estimates that the move could prevent 440 deaths, 11,900 injuries and $190 million in damage annually.

The District now allows 18-year-olds to buy alcoholic beverages. Virginia permits beer purchases by 19-year-olds, but has set 21 as the mininum age for buying other alcoholic beverages.

The council urged Maryland and Virginia to follow the District's lead in considering any driver intoxicated if the alcohol concentration in the driver's blood amounts to 0.1 percent or more.

It also asked the two states to join the District in automatically suspending the license of any driver arrested for drunk driving. Suspensions now occur in Maryland and Virginia only after hearings or court proceedings, officials said.

In other developments, the council suggested that Maryland take steps to improve safety on the Potomac River by allowing District, Virginia and federal officials to enforce Maryland laws between Chain Bridge and Seneca Falls.

The council also expressed concern about a Maryland proposal for a coal-fired electric power plant near the Potomac, possibly at Point of Rocks in Frederick County.