February 5, 1982

The United States said today that it had expelled the senior military attache in the Soviet Embassy here on espionage charges. A State Department spokesman, Sondra McCarty, said in response to an inquiry that the attache, Maj. Gen. Vasily I. Chitov, had been declared persona non grata and had left Wednesday. Asked the reasons for the expulsion, Mrs. McCarty said on ly that the attache had been expelled ''for activitie s inconsistent with his diplomatic status.''

SOUTH STREET, once the heart of seafaring New York, is a lot more these winter weekends than just a place to visit ships - although the climb up the gangway is always worth making. This weekend, for instance, without once leaving terra firma, you can attend an oldfashioned Sunday reading of the great American sea novel, ''Moby-Dick,'' take a tour down 18th-century streets, browse for book bargains, get a card for your Valentine hot off the press and warm your shivering timbers with hot grog. For the first few pages of ''Moby-Dick,'' Herman Melville's pensive hero, Ishmael, has the blues. To cure them, he sets off to sea, starting by way of the South Street Seaport, a bustling neighborhood of shops, saloons and boardinghouses. This weekend offers an ideal opportunity to follow Ishmael's trail through the southeast tip of Manhattan and to see many of the buildings that remain from his time. Moreover, on Sunday, in the spacious Seaport Gallery at 213-215 Water Street, four professional actors will present a dramatic reading from ''Moby-Dick.'' They hope that Melville's prose will carry the day, but they'll also spice up a few passages - like the detailed descriptions of rigging sails - by using the gallery's impressive sailing-ship models as props.

Despite one of the worst cold spells in memory, demand for home heating oil and other petroleum products has weakened substantially, dropping prices sharply in the past 10 days. Oil traders report that prices for crude oil and heating oil on the spot market, where oil that is not under long-term contract is traded, have dropped by more than 5 percent, after having held relatively steady for several months. A similar trend is becoming evident for gasoline prices. Putting Pressure on OPEC The sharp drop puts heavy pressure on the Organization of Petroleum Exporting Countries and other oil producers to reduce their official contract prices, as some have quietly begun to do through disguised discounts.

Leonard H. Marks, a former director of the United States Information Agency, was elected chairman of the Foreign Policy Association yesterday. Mr. Marks, a Washington lawyer, who has been vice chairman since 1979, succeeds Carter L. Burgess as head of the association's 75-member board of governors. Mr. Burgess, the chairman since 1974, is to become head of the board's executive committee.

The Senate today approved a proposal that could virtually eliminate busing as a tool for racial integration of the public schools. The proposal drew strong support from both parties and passed by a vote of 58 to 38, a sign that busing had become highly unpopular in many communities. The measure would bar the Federal courts from ordering busing plans that transport schoolchildren more than five miles from home or take longer than 15 minutes. It would also allow the Justice Department to ask the courts to overturn existing busing plans that exceed these limits.