What was going on when I was born?

''I NEVER saw her or heard her. Yet I continually bless the name of Ida Rubinstein for, because of her, I've had a whole second career,'' Vera Zorina said the other day during a break between rehearsals for her part in the Stravinsky Centennial Celebration at the New York State Theater. A glamorous star of ballet, Broadway and Hollywood during the 1930's and 40's - when she was married to the choreographer George Balanchine - Miss Zorina has more recently enjoyed success as a reciter in works that combine declamation with music. Tonight, she stars with the New York City Ballet in one of the most famous of all such works, Igor Stravinsky's ''Persephone,'' to a text by Andre Gide.

A Justice Department internal investigation has concluded there was no conflict of interest involved when William F. Baxter, the Assistant Attorney General in charge of the antitrust division, dismissed the Government's suit against the International Business Machines Corporation, a department official said yesterday. J. Paul McGrath, an Assistant Attorney General, disclosed the findings of the investigation to an appeals court in New York. He told the three-judge panel that the Justice Department considers the dismissal final and does not plan to reopen it. ''The findings do not raise any questions about the propriety of the dismissal,'' Mr. McGrath said. ''There was no conflict of interest which barred him from doing that,'' he added, referring to Mr. Baxter.

In a $5.1 billion deal that would be one of the biggest corporate acquisitions on record, the Gulf Oil Corporation said yesterday that it planned to buy the Cities Service Company. The agreement, announced jointly by the two oil giants, was viewed on Wall Street as an effort to frustrate a takeover of Cities Service being attempted by the much smaller Mesa Petroleum Company of Amarillo, Tex. Cities Service has opposed the Mesa attempt. A Gulf-Cities Service combination would be exceeded in value only by the $7.2 billion purchase of Conoco Inc. by A sharp rise in interest rates depressed the prices of stocks and gold. Details in Business Day E.I. du Pont de Nemours & Company last summer and the United States Steel Corporation's $6 billion acquisition of the Marathon Oil Company this year.

Gulf Oil has agreed to take over Cities Service in a $5.1 billion deal that would be one of the biggest acquisitions ever. The move was seen on Wall Street as an effort to frustrate an unwanted takeover of Cities Service being pressed by Mesa Petroleum. A Gulf-Cities Service merger would be exceeded in size only by the purchases of Conoco by Du Pont and Marathon Oil by U.S. Steel, and would create the nation's seventh-largest industrial corporation. (Page A1.) Itel's chairman and chief executive quit the troubled company, citing ''philosophical differences'' with major creditors. The company, which is operating under court protection from its creditors, also filed a reorganization plan in Federal Bankruptcy Court. (D1.)

The City Council and the Board of Estimate, racing to beat a midnight deadline, formally adopted New York City's next budget last night. The process that started months ago culminated at 11:50 A.M., when the City Council voted 37 to 5, with one abstention, to approve a $15.54 billion expense The New Jersey State Assembly approved a 5 percent gasoline surtax, and Governor Kean signed a bill raising the state cigarette tax. Page B2. budget for the fiscal year that begins July 1. The vote followed a marathon negotating session that started Wednesday morning and produced a package of changes valued at $48.2 million in the budget that Mayor Koch had submitted on May 10.

Dr. Joseph S. Murphy was selected last night by a search committee to be the next chancellor of the City University of New York. The nomination, which is considered virtually certain to be accepted, will be subject to approval early next week at a meeting of the university's board of trustees. Dr. Murphy would succeed Dr. Robert J. Kibbee, who died Wednesday at his home in Manhattan. Dr. Kibbee was to have retired on June 30. Dr. Murphy was president of Queens College, one of the undergraduate units of the City University, from 1971 to 1977, when he became president of Bennington College in southern Vermont.

International A major shake-up in Argentina is under way. Leopoldo Galtieri resigned under pressure as President, Army commander in chief and junta member. Government sources said he would be replaced as President temporarily by Maj. Gen. Alfredo Oscar St. Jean, the Interior Minister, while the junta decides on a permanent successor. (Page A1, Column 6.) Argentina denied Britain's request to allow British ships to return prisoners taken in the Falklands directly to Argentine ports, the Foreign Office announced. However, later Argentina announced that it would send ships to the islands to pick up the prisoners in an operation aided by British ships and the Red Cross. (A1:4-5.)

The Federal Communications Commission today repealed regulations that have restricted the number of cities where pay television stations may operate. The decision, reached unanimously with little debate, could stimulate additional growth in an industry that has already developed from only two pay TV stations in 1977 to more than 40 either authorized or operating today. Pay TV stations, formally known as subscription television stations, transmit a scrambled signal that can only be received with the aid of a special decoder.

MARKET visitors can be divided between those who go with a clear purpose - seeking a particular item that fills a need or adds to a collection - and those who go for the fun of it, to browse among other people's discards. Nostalgia, of course, plays a big part in the venture. Like Citizen Kane's Rosebud, items are often sought for the memories they may hold - a certain toy or an old cookie jar that conjures up the pleasures of another time. The start of summer is the peak flea-market season in New York, Connecticut and New Jersey, so right now enthusiasts can explore to their heart's content. Flea markets are being staged in a variety of settings in both town and country, from an idyllic meadow in a quaint village to a bustling lot in downtown Manhattan, to a shopping mall in the suburbs and even a race track. Many flea markets operate on weekends through the summer while others are special occasions. This season, the overriding trend seems to be for country furniture. ''Every dealer who comes with a supply of country furniture has a terrific day,'' says Roy Young, the owner of the Elephant's Trunk Bazaar Giant Country Flea Market, in New Milford, Conn. ''Country furniture is extremely hot.''

SHOULD music stroke the senses or should it cut cleanly to the soul? From opposite ends of Manhattan this weekend, two singing groups will beg to differ. In SoHo, from the city's more relaxed and hedonistic regions, the Western Wind vocal ensemble offers suppers and singing tonight, tomorrow and Sunday evening at the Performing Garage. There will be music for the ear, costumes and staging for the eye and a catered meal for the palate - a veritable synthesis of sensuous pleasures. Supper is at 7, and at 8, with the aftertaste of pasta, salad and perhaps a glass of wine close by, listeners will hear first ''The Boat From Venice to Padua,'' 27 musical scenes from the early-17th-century madrigalist Adriano Banchieri. After an intermission that includes desserts and coffee comes the madrigal art updated -William Bolcom's ''Satires for Madrigal Group,'' written expressly for the Western Wind in 1972.

Members of a House-Senate conference committee agreed late Thursday night on a budget for the fiscal year 1983 and early this morning adopted the entire budget resolution on a voice vote. The budget would provide for spending of $769.8 billion and a deficit of $104 billion. Some experts have said the projected deficit is unrealistically low. The committee generally accepted a compromise worked out by House and Senate Republicans, who have effective control of the budget process. The Republican members of the conference committee sought to reconcile differences in emphasis rather than ideology in the respective budget resolutions of the House and the Senate.

President Leopoldo Galtieri resigned under pressure today as President, Commander in Chief of the army and member of the ruling military junta. Hours later, Argentina announced that it would send ships to the Falkland Islands to help repatriate the Argentine troops taken prisoner there by the British. It said the prisoners would be brought home in both Argentine and British ships. Britain, which said earlier that Argentina had refused to allow British ships to return the prisoners directly to Argentine ports, said it was considering the Argentine proposal.