September 18, 1983

President Reagan said today that the downing of the South Korean airliner had produced ''a fundamental and long overdue reappraisal'' of the Soviet Union in countries around the world and had isolated Moscow in world affairs. Underscoring the White House's efforts to turn the shooting down of a Korean Air Lines 747, in which 269 people died, into a major political coup for the United States, Mr. Reagan said the Russians hoped that ''their crime and cover-up will soon be forgotten and we'll soon get back to business as usual.'' 'Case Is Far From Closed' ''Well, I believe they're badly mistaken,'' he said in his weekly radio address to the nation. ''This case is far from closed.'' ''Good and decent people everywhere are coming together and the world's outrage has not diminished,'' the President said.

VICTORIA FELDMAN had hoped for her own bedroom, but she shares a studio apartment and sleeps on a sofa bed. Robin Kaplan had planned to be independent, but instead she takes money from her parents each month to help pay her rent. Robert Cohen would have liked to live in Manhattan, but the prices drove him first to Queens, then to Brooklyn and, just last week, back to Queens. Each year thousands of young singles come to New York, bearing suitcases and big ambitions, to start their careers and set up their first homes away from home. Fresh out of school and starting their first job, they have detailed visions of the place they want to rent and call their own: A cozy one-bedroom in Greenwich Village. A sleek studio, with a doorman, on the Upper East Side. A monthly rent equal to their weekly salary.

''You can be a la mode for two, maybe three years,'' says Maurice Bejart, director of the Brussels-based - and often controversial - Ballet of the 20th Century. Tuesday evening, the iconoclastic 56-year-old choreographer leads his troupe back to New York for its seventh American visit since 1971, beginning a three-week engagement at City Center. ''We've been performing successfully - for all types of people - for more than 20 years,'' he adds proudly. Mr. Bejart's productions have been regularly greeted with popular acclaim here and in Europe. It must be noted, however, that some American critics, especially, have taken Mr. Bejart to task for supposedly melodramatic sensationalism and a seeming disregard for classical balletic technique. Yet the French-born artist has established his own - perhaps characteristically European - ethos. Physical sensuality, literary and philosophical themes and overt theatricalism are decidedly Bejartian. The choreographer's dictum, ''Une arabesque belle est une arabesque bien sentie'' (''A beautiful arabesque is one well felt''), may not sit well with those who prefer to argue about placement or count fouettes, but it expresses an important aspect of Mr. Bejart's performance credo. ''Ballet is part of the theater,'' he says. ''I want my dancers to be on stage like human people . . . who give emotion to the audience.''

Ray Williams, the flashy, high-scoring guard who led the Knicks to the playoffs in 1981 and then did the same for the Nets in 1982, has been reacquired by the Knicks from Kansas City, the team that had acquired him from the Nets a year ago. In a three-way deal announced yesterday, the Knicks traded Vince Taylor, a second-year guard, and next year's first-round draft choice to the Indiana Pacers for their 6-foot-6-inch guard, Billy Knight, and then sent Knight and an undisclosed amount of cash to Kansas City. ''The New York Knickerbocker organization is very pleased in reacquiring Ray Williams,'' Dave DeBusschere, the Knicks' executive vice president and director of basketball operations, said. ''We all feel that he will be a great addition to our team. Now we have a solid, strong backcourt.''

For several decades many of downtown Newark's greengrocers, butchers and fishmongers have been doing business along a stretch of Mulberry Street known informally as the Mulberry Street market. But as the city's long-term urban renewal project, the Gateway complex, moved closer to Mulberry Street, it seemed for a time that these food merchants would be forced out.