The Supreme Court yesterday let stand a decision requiring the Bechtel Corp. to honor an agreement that it not boycott firms blacklisted by Arab nations because they do business with Israel.

The justices refused to review an appeal by the powerful engineering and construction company, which claimed it didn't have to abide by a consent degree worked out with the Justice Department because it said the government agency later modified the agreement.

The justices yesterday agreed to hear several other business-related cases, including a local dispute between Virginia apple growers and the Commonwealth of Puerto Rico. The growers challenged the right of Puerto Rico to sue them on behalf of its citizens who were refused employment or were fired by the growers three years ago.

The Bechtel case began five years ago when the Justice Department accused the company of violating antitrust laws by refusing to deal with American firms blacklisted by Arab League nations because they do business with Israel. The government also said Bechtel refused to deal with blacklisted persons, required subcontractors to refuse to deal with blacklisted persons and obtained blacklists to help with the boycott.

The Justice Department and Bechtel agreed to a consent decree in 1977. However, Bechtel said that before the decree was actually signed, the Justice Department modified the decree, changing its meaning. A district court said the language in the proposed decree had not been altered, and an appeals court agreed.

The Virginia apple growers case involves a long-standing dispute challenging the hiring practices of apple growers in Virginia, Maryland, West Virginia and New York. The commonwealth of Puerto Rico claims that the growers discriminate against a group of American citizens over foreigners, notably Jamaicans, which the growers prefer to work for them.

The growers, however, claim that the commonwealth has no standing to sue them because their hiring practices don't appreciably affect Puerto Rico and the workers have filed their own suits.

The growers had complained that red tape made it difficult to hire Puerto Ricans to pick the annual fall crop, so in 1978 the Puerto Rican legislature changed laws requiring the growers to comply with a series of regulations before hiring Puerto Rican workers.

However, in the past the growers said the Puerto Ricans were "unproductive" and nearly all of them that were ever hired had to be fired. They took their case to the U.S. District Court for the Western District of Virginia, which allowed them to hire Jamaican workers

Shortly afterward, Puerto Rico sued the growers, claiming that 18 apple growers failed to employ Puerto Ricans that had been cleared to work by the government, 27 growers subjected some Puerto Rican laborers to work under conditions worse than those imposed on foreigners and 27 growers improperly fired the Puerto Ricans before their contracts expired.

The district court, siding with the growers, said the Commonwealth lacked the standing to pursue the case. But the Fourth U.S. Circuit Court of Appeals said the hiring practices affected the commonwealth's economy and they therefore had standing to sue. The growers appealed to the Supreme Court.

In other business cases, the court:

Refused to review a lawsuit by 12 stockholders of Marshall Field & Co. claiming the large Chicago department store violated federal law by fighting a takeover attempt by Carter Hawley Hale, a national retail chain, in 1977. The stockholders contended that the chain, which owns Neiman Marcus stores, offered them as much as $42 a share for stock that had been worth $20 before the tender offer, but the Marshall Field board of directors, through a public relations campaign, fought off the takeover attempt.

Agreed to consider a California case challenging the right of the state's alcohol control board to prevent a liquor distributor from purchasing certain name brands of beverages unless he is designated to do so by the brand owner or agent.