July 22, 1982

Air-conditioning units on New York City buses, both old and new, require such a high degree of maintenance that transit officials say they are fighting a losing battle to keep buses cool this summer. The problem is so extensive, according to one top bus official, that the city would be wise to forget about air-conditioning its buses altogether. ''Go over to Europe,'' said the official, Charles J. Milau, general superintendant for maintenance. ''Do you see airconditioning on those buses? Of course not.''

Mayor Koch said yesterday that he would support efforts to make single-room-occupancy hotels ineligible for the benefits of a taxincentive program for real-estate developers. The Mayor's statement came less than three weeks after the State Legislature decided not to approve extension of the program, known as J-51, which also covers residential apartment buildings. Among other reasons, the program has been controversial because it has displaced thousands of tenants from single-room-occupancy hotels.

The nation's gross national product rose in the second quarter at an annual rate of 1.7 percent after adjustment for inflation, the Commerce Department reported today, the first upturn in this key indicator since last summer. The increase surprised many economists, leaving them divided over whether the recession was over and what the outlook might be for a recovery. Some economists who had expected a small improvement in the G.N.P, which measures the total value of the nation's goods and services, were surprised that the increase was much larger. Others, who recently predicted a decline, contended that the recession was not over, despite the increase for the April-to-June quarter.

The Continental Illinois Corporation, the nation's sixth-largest banking organization, announced yesterday that it lost almost $61 million in the second quarter. Bankers said it was the biggest quarterly loss by a major banking company in recent history. The loss was largely a result of the company's dealings with the Penn Square Bank of Oklahoma City, which failed last July 5. Continental was the second major bank to have announced a loss this week. On Tuesday, the Chase Manhattan Corporation, the nation's third-largest, said that it had lost $16.1 million in the April-June period, also partly because of a relationship with Penn Square. It was the first time, at least in recent history, that any of the nation's 10 largest banks reported a quarterly loss.

In their first debate of the primary campaign, the three Republican contenders for the United States Senate from New York yesterday criticized each other and the Democratic incumbent, Senator Daniel Patrick Moynihan. One of the candidates, Whitney North Seymour Jr., accused the Senator of ''scaring the dickens out of senior citizens'' and ''an outrageous crying of wolf'' in pointing up his efforts to prevent Social Security cutbacks. Another contender, Assemblywoman Florence M. Sullivan, described Senator Moynihan as ''an intellectual elitist who has been living in an ivory tower - who has been conducting himself more like a man of letters, a professor of whatever, than he has as the United States Senator representing the interest of the people of this state.'' The third candidate, Muriel Siebert, criticized the Senator for what she said was his failure to help her, as State Superintendent of Banks, in her efforts to help savings banks on the brink of closing their doors.