October 10, 1985

The spring collections peaked here with the showing Tuesday night of the Giorgio Armani collection in the theater of his headquarters on the Via Durini. Not a seam was out of place as the master tailor brought out his now-classic daytime look based on a precision-made broad-shouldered jacket. But there was a surprise. Using spangled fabrics that glittered as they caught the light and some prints, he reinterpreted his jackets and shirts for evening. His evening separates were applauded last season; this year they overshadowed the daytime clothes. There are no tricks and no shockers, just a lot of pretty clothes that put a new slant on night dressing. Sufficiently formal for almost any occasion, they appeal especially to women who do not care for traditional evening dresses with their bare necklines and draped body lines. Armani's jackets and skirts, no matter how glittery, preserve the casual feeling of his daytime clothes. For many women, they will offer a comfortable way to dress up at night.

The United States tonight assailed ''the brutal killing'' of an American aboard the hijacked Italian cruise ship, and it criticized Italy and Egypt for failing so far to announce that the hijackers would be prosecuted. State Department officials said they were furious at the speed with which the Italians and the Egyptians, working with the Palestine Liberation Organization, agreed to let the hijackers go free. A statement read by Larry Speakes, the White House spokesman, said, ''We are saddened and outraged at this brutal killing'' of Leon Klinghoffer of Manhattan, a passenger aboard the hijacked ship, the Achille Lauro. Confirmation by Ambassador Confirmation of his death came from the United States Ambassador to Egypt, Nicholas A. Veliotes, who was sent today by President Reagan to make a first-hand inspection of the cruise ship several hours after Egyptian authorities announced that the hijacking crisis had ended.

Four men identified as the hijackers of an Italian cruise ship surrendered in Egypt on Wednesday after a two-day drama in the eastern Mediterranean. Hours later, Italy announced that an elderly, wheelchair-bound tourist from New York was missing and believed slain in the hijacking, his body thrown overboard. Wednesday night the United States confirmed ''the brutal killing.'' The other 400 passengers and crew members aboard the ship, the Achille Lauro, were reported to be safe. Ship Sails to Port Said The ship sailed into Port Said before dawn today, and port officials said Egyptian security officials wanted to search the liner. The passengers and most crew members were expected to be brought ashore during the search; security officials were reported to be worried that the hijackers might have left a time bomb hidden aboard.

The Government today overhauled its regulation of the natural gas industry in a move likely to increase competition and thus lower prices for residential, business and industrial consumers. In approving the new regulations, however, the Federal Energy Regulatory Commission deferred action on ''block billing,'' the most hotly contested of four major elements of its plan. Block billing would channel larger amounts of inexpensive gas still under price controls to consumers, giving them a price reduction estimated at $5 billion a year. This bonanza would have come at the expense of producers and pipeline companies. In opposing the measure, they argued that it would make the deregulated gas unmarketably expensive and lead to bankruptcies and a major decline in gas exploration.

IT is a mansion, or nearly a mansion, that Arthur and Esther Bramwell did not know they wanted. ''A friend introduced me to the house three years ago,'' said Mr. Bramwell, a deputy county clerk in State Supreme Court in Brooklyn. ''I told him I already had a house nearby that was paid for, that I didn't need it. He said I had to see it.'' The doors in the 12-foot-high parlors are faced in oak on one side and mahogany on the other. Virtually every opening in the late-19th-century house - doorways, windows and fireplaces - is surrounded with highly detailed and intact late-Victorian woodwork. Mr. Bramwell, pointing out the patterned brass hinges on the oak front door and the coat hooks made of sterling silver in the entry hall, is proud of the elegant 12-room, four-story brownstone he now owns in the Bedford-Stuyvesant section of Brooklyn.