December 18, 1986

The windy city is becoming the trendy city. Retailers on North Michigan Avenue, this city's premier shopping boulevard, say that with the glittering array of shops lining their ''Magnificent Mile,'' they can now hold their own against the likes of Rodeo Drive, and even Fifth Avenue. North Michigan Avenue already boasts such heavyweights as Saks Fifth Avenue, Neiman-Marcus, Bonwit Teller, I. Magnin, Lord & Taylor and, of course, Chicago's own Marshall Field's. There are also such smaller luminaries as Gucci, Tiffany and Burberry. And Bloomingdale's will add yet more excitement when it opens its first Chicago store in 1988.

The Federal Bureau of Investigation has begun an inquiry into why Attorney General Edwin Meese 3rd ordered a delay in an F.B.I. investigation last fall into arms shipments to Nicaraguan rebels, law enforcement officials said today. One official said the F.B.I. was told at the time that its investigation, into the activities of a company in Miami, could imperil negotiations for the release of American hostages in Lebanon. Mr. Meese's order to the F.B.I. raises the question whether he may have known earlier than he has acknowledged about the diversion of proceeds from secret Iran arms sales to Nicaraguan rebels. Asserts His Lack of Knowledge Today, after appearing before the Senate Intelligence Committee, Mr. Meese said his own investigation into the diversion of funds to the Nicaraguan rebels had found nothing beyond his original finding on Nov. 25 that only Lieut. Col. Oliver L. North and Vice Adm. John M. Poindexter had known about the scheme. [ Page A20. ] The attempt to delay the F.B.I. inquiry also raises the question why Mr. Meese would not have asked what the hostages in Lebanon had to do with supplies for the Nicaraguan rebels.

John Z. DeLorean was found not guilty today of defrauding his failed sports car company of $8.5 million. But prosecutors immediately challenged the not-guilty verdicts on the 15 counts, including fraud and racketeering, saying the jurors may have misinterpreted the legal instructions given by Federal District Judge Julian A. Cook Jr. The jury decided to acquit Mr. DeLorean, 61 years old, despite the fact that 3 of the 12 jurors thought he was guilty, several jurors said in interviews tonight. They said they thought they had to acquit Mr. DeLorean if they could not unanimously agree on a verdict. They apparently ignored the possibility of declaring a hung jury, according to the interviews.

IT has been over 50 years since Jean Harlow sat at her vanity in ''Dinner at Eight'' and reached through the three tiers of white silk fringes that skirted it, to open the drawers beneath. The elaborate vanities of the era, which acted like adjectives of beauty and femininity modifying anyone who sat before them, gradually fell out of fashion, victims of the Depression, World War II and, later, the trend to practical, modular and minimal furniture. Vanities themselves became a forgotten furniture type. Women simply retreated to the bathroom and made up over the sink. At the peak of their popularity, however, during the 1920's and early 1930's, vanities were extraordinary objects, created by the most gifted designers for some of the great figures of the era.

Alcohol-related accidents involving drivers under 21 years old have declined by nearly half in New York State since the drinking age was raised above 18, according to figures from the state's Department of Motor Vehicles. During the same period fatalities resulting from such accidents dropped by over 40 percent. The figures for fatalities are comparable to those in New Jersey, which raised its drinking age to 21 four years earlier than New York.