A federal judge has ruled that the District cannot enforce a ban on the sale of single cans and bottles of beer and malt liquor in some parts of Northwest Washington.

U.S. District Judge Rosemary M. Collyer concluded that the D.C. Council hastily passed the ban on sales in Ward 4 last fall without the required public notice. The ban, scheduled to begin last Nov. 12, never took effect because Collyer issued an order blocking its enforcement until the larger legal questions could be decided. This week, she struck down the law.

The measure, known as the Fenty Amendment after sponsor Adrian M. Fenty (D-Ward 4), is similar to other single-sale alcohol bans in the Mount Pleasant and Adams Morgan neighborhoods and is aimed at reducing litter and drinking on sidewalks. Fenty said yesterday that he will ask the council to act again on the ban and that he will urge city lawyers to appeal the ruling.

"Of course, it's disappointing," Fenty said, predicting that the ban will eventually move forward.

Decatur Liquors and Chekole T. Teshome, owner of Town and Country Market in Ward 4, filed the federal lawsuit to stop the ban, arguing that the city failed to hold public hearings and give ample notice to merchants and residents.

John Wilson Jr., owner of Decatur Liquors, said he was "elated" by the judge's ruling. "How in the world did [Fenty] get this by, without anybody being notified?" Wilson asked. "It seemed kind of underhanded."

Paul L. Pascal, president of the D.C. Association of Beverage Alcohol Wholesalers, said the ruling's attention to procedures could have a broader effect on the way the council conducts business.

Opponents said the ban would devastate mom-and-pop stores that count on single sales for as much as 50 percent of their income in some months. But some neighborhood residents favored the action.

Jourdinia Brown, a neighborhood activist from Shepherd Park, said she remains concerned about the kind of activity that single sales could encourage along Georgia Avenue NW.