June 1, 1984

In a new and unorthodox ploy to encourage its customers to stay loyal to Ma Bell, the American Telephone and Telegraph Company said yesterday that it would give its residential customers discounts on everything from microwave ovens to airplane tickets. The phone company's plan, similar to incentive programs used on and off by gas stations, airlines and even Citibank and American Express, will be available to nonbusiness customers who run up long-distance bills of more than $15 a month. The amount of the discounts increases as customers talk longer. And with cut-rate competitors like the MCI Communications Corporation and GTE-Sprint already taking away customers, the telephone giant showed yesterday that it was wasting no time with its response: On Wednesday, it began mailing out 25 million copies of a glossy, 14-page catalogue brimming with color pictures of products and services available at a discount to A.T.& T. users. ''This is a reward for our best customers, another reason for them to stay with A.T.& T.,'' said John Smart, the vice president of marketing for A.T.& T. Communications, the unit that runs the company's long-distance services.

A front-page photo caption yesterday incorrectly identified the location where residents were viewing an annular eclipse. The photo was made in Houston.

''Philosophically, a group of us on the board thought that smokers had rights, too, but afterward I talked to the staff about scheduling problems, enforcement and the sneak smoker.

Phibro-Salomon Inc., the big New York commodity trading and investment banking house, said yesterday that it was no longer considering splitting up the company. Only 10 days ago, Phibro said that it was studying whether to sell its commodity trading operations, except oil, to a group of executives and employees. Yesterday, in a one-sentence statement, Phibro said only that the study had been ''terminated.'' Top executives would not elaborate, but insiders said that while no price had ever been proposed officially, the two main factions within the company could not agree on one. One insider, who asked not to be identified, said that he thought the commodity trading operations being sought were worth at least $750 million.

A Nicaraguan insurgent leader wounded Wednesday night in a bomb attack that killed five people was taken into Costa Rican custody today as the Government apparently sought to stress its official neutrality in Central American conflicts. The bomb, which wounded 27 people, exploded during a news conference being given just inside the Nicaraguan border by the rebel leader, Eden Pastora Gomez. Mr. Pastora, whose Revolutionary Democratic Alliance is based in Costa Rica, was brought for treatment to a San Jose clinic, where he was placed under police guard. ''He is under the control of the Public Security Ministry,'' the Information Minister, Armando Vargas, said. ''Later it will be decided what his destination should be.''