At the height of the Yom Kippur War, Premier Golda Meir's personal spokesman broke off whatever he was doing at 1 p.m. each day. He turned in to the BBC for quick, accurate information on the moves and responses of Arab nations and the rest of the world.

In Stockholm, a key press aide to ex-Premier Olaf Palme begins his day with an unvarying routine. He does not listen to Sweden's state radio with its leftist twist but to the World Service bulletins of the British Broadcasting Corp.

An experienced foreign correspondent away from his base always carries a transistor radio to keep in touch with the world at large. He is not likely to listen to the Voice of America or Radio Moscow or Radio Peking. The chances are that he depends on the BBC or a professional, unslanted account of events of consequence.

It fact, the BBC's enviable stature is a major argument used by Voice of America staff members in their current campaign for an independent VOA divorced from the U.S. Information Agency and free of government restrictions on news coverage. More than 500 VOA employees, echoing a 1975 report of a panel headed by former CBS President Frank Stanton, recently signed a petition asking Congress and the Carter administration to create independent Voice.

While the VOA struggles for a new identity, there is a quiet confidence throughout Bush House, the massive stone pile near Fleet Street where the BBC broadcasts in English and 38 other languages around the globe, that the BBC's 1,000 broadcasters are transmitting the world's best overseas news service.

"The phrase 'I heard it on the BBC' is taken," the BBC's handbook smugly claims, "as the modern equivalent of the medieval quod erat demonstrandum ." Tradition

NOBODY, of course, is as good as that, but the claim reflects both an extraordinary belief in the service's independence and the fact that those with a professional need to know are among the BBC's 69 million regular listeners beyond the English Channel.

How this came about cannot be explained by organization charts, by drawing lines and boxes between the BBC's External Services and government departments. It is largely a question of tradition, habit and prestige built up over 45 years and through endless battles with government officials.

On the surface, the BBC's foreign broadcasts enjoy no independence at all. They are financed entirely by the government's Foreign Office, a sum equivalent to $45.4 million dollars last year.

The Foreign Office, moreover, completely controls what languages the BBC will broadcst and how many hours shall be allotted to each. When Portugal became a center of Western concern after the April, 1974, coup, the Foreign Office ordered the BBC to step up its broadcasts. When budget slashed forced cutbacks, the Foreign Office decided to end Sinhala broadcasts in Sri Lanka and to reduce the Arabic and other services.

In theory, then, the Foreign Office paymaster should determine all the tunes that the BBC pipes. In practice, the service is probably the world's most independent.

Every student of the BBC begins his explanation of this uniquely British paradox by pointing to tradition. Asa Briggs, whose three-volume history of the organization is the standard reference work, attributes of BBC's objectivity to "a very well established tradition, buttressed by three or four individuals."

The most important of these, Lord Briggs believes, was Charles Reith, the BBC's first general manager, who ran the empire for 15 crucial years.

Reith was a 34-year-old Scots engineer, ambitious, tenacious and deeply religious, when he took over the fledging BBC. A man who believed implicitly in his own unquestioned integrity, he saw broadcasting, as Briggs put it, "in terms of high moral responsibility." Forced to Compromise

NEVERTHELESS, Reith was forced to compromise in the bitter 1923 General Strike, and he never forgot it. He did succeed in foiling the plans of some cabinet ministers to take over the BBC as a crude instrument of government. But he ran so cautious a show that he kept off the air all the strike leaders, their supporters among Labor and even the Archbishop of Canterbury who wanted to propose a negotiated settlement when the Tory government was pressing for unconditional surrender.

Reith and the BBC were scarred by that experience. Never again, he vowed, would broadcasting in Britain lend itself so shamelessly to the political ends of the rulers of the day.

The organization's independence, in the view of veteran producer and interviewer John Tusa, who has worked on both the domestic and foreign broadcast services, should be credited to "the Reithian tradition of enlightenment."

There is, Tusa added, "a much more puritanical approach to broadcasting" in the foreign than in the domestic transmissions. While entertainment is an essential part of programming for a British audience, he explains, the overriding concern in the overseas broadcasts is information.

Oddly enough, it was the BBC and not the government that took the initiative to broadcast overseas, a key element in the tradition. When the first Empire Service Broadcasts went out in English in 1932, the government was so uninterested it ordered the BBC's domestic side to pay the expenses from its only source of revenue - license fees on radios - rather than provide a subsidy.

By 1938, however, the Foreign Office had awakened to the power of German and Italian propaganda broadcasts, particularly to the Arab world. So the government asked the BBC to create a service in Arabic.

On the very first broadcasting day, the British military in Palestine executed an Arab terrorist. The Foreign Office man assigned to edit the service characteristically suggested this item be dropped from the bulletin. But his BBC superiors overruled him without hesitation. Another strand of the tradition was woven.

Even during World War II, British propaganda was quiet and restrained, confined to commentaries or documentaries. The news bulletins were not tampered with; disasters like the fall of Singapore were reported promptly. In occupied Europe, people risked their lives to listen to BBC news reports they regarded as truthful. Built-in Audience

DECADES LATER the risk is less but the need still exists. The media are subject to government control, pressures or censorhip in a wide variety of countries. And in some areas the press, while free, tends to be provincial, home-oriented. So the BBC continues to have a built-in audience.

It serves that audience with broadcasts in English 24 hours a day, seven days a week. Its foreign language broadcasts vary from a weekly half-hour of news and commentary in Maltese through seven hours a week in Swahili, 15 hours in Hindi, 16 in SerboCroat and 32 in Russian. The BBC's most extensive foreign language service - 63 hours weekly - is in Arabic.

Although the Foreign Office frequently complains to the BBC - a matter of pride in the institution - the diplomats recognize, at least in principle, the utility of independent broadcasting.

"It is in the best long-term interests of the British people," one key diplomat said, "that the BBC have a reputation for truth and reliability, even though they put over a point of view we don't like. It is an asset. It gives us moral stature."

In practice, of course, this self-denying attitude is frequently upset. While directing the BBC's language service to one Mediterranean dictatorship, one BBC man frequently visited the capital of the country to which he broadcast. There, he would invariably call on the British ambassador and just as invariably he would be dressed down. The broadcaster was making the mission's life uncomfortably by reporting news of opposition to the dictatorship and its abuse of human rights. The ex-director said:

"I never knew whether the ambassador was rebuking me for the record, so he could tell the regime he had protested, or whether he really meant it. But if he had made any real trouble, I would have gone to my mates in Fleet Street and straightened him out."

The External Services has on rare occasion bowed to government requests. Just before the start of the Six-Day War in 1967, the BBC planned to broadcast Svetlana Stalin's "Letter to a Friend." High government officials said this could jeopardize the delicate negotiations, involving inter alia the Soviet Union, on which Middle East peace depended. So the broadcast was held up for two days.

Similarly, the BBC normally interviews the author of an important book about a country to which it broadcasts. But when journalist David Martin wrote a critical book on Uganda, the British High Commissioner there warned that Martin was so hated by President Idi Amin that such a broadcast might endanger British lives. Once again, the interview was postponed - until it appeared that Amin's rage had temporarily cooled. "Killing the Goose"

IN RECENT MONTHS, pained Foreign Office officials have told the BBC that its broadcasts of torture and dissidence in Brazil, Iran and the Soviet Union have been "unhelpful" to British trade efforts in all three countries. But Gerard Mansell, director of External Services, insists, "Rule one is to get it right." As long as the items were accurate, the pained complaints could be dismissed.

The BBC can count on a bipartisan lobby in Parliament, genuinely devoted to a free and uninhibited press, to embarass any bureaucrats who try to bend the BBC's news.

Roderick MacFarquhar, an Asian expert, a Labor member of Parliament and a former BBC journalist, said: "If a real crunch came, the Gerry Mansells would contact people like me, on both sides of the House; an enormous stink would be rised publicly." Mansell, who came up through the BBC ranks, described the pressure as eminently containable. "The Foreign Office starts with the assumption that to require the BBC to bend its editorial position would amount to killing the goose that lays the golden eggs."

"They make the attempts from time to time. It's done in the usual, deprecatory, low-key British Way. It's all very civilized. Over a lunch or over the phone, one of us will be asked, 'Don't you think . . .'

"They realize there's a certain chemistry, that if you force the issue, it is counterproductive."

This does not mean that the BBC is compeltely untethered. Since 1971, no interview with a member of the IRA or other terrorist group in Ulster can be broadcast at home or abroad, without the express permission of Mansell's boss, the BBC's director general. News vs. Diplomacy

BROADCASTERS for External Services do not regard themselves as government servants but as employes of the BBC. Their pay and conditions are bargained collectively by unions.

A shrewd observer has noted that newsmen abroad regard the BBC reporters as colleagues; those from the Voice, no matter how highly respected, are still seen as civil servants.

Mansell suggested that the difference between the Voice and the BBC is "buried deep in the nature of the relationship between broadcasting and diplomacy."

"If you expect your [VOA] broadcasts to pay due regard to the needs of diplomacy, you can't get journalism. The great difference is the view taken by Washington of external broadcasting. If it is a projection of the views of the administration, geared to the ultimate interests of the administration, you have a price to pay."

For the most part, the BBC is not compelled to pay that price. At a time when British exports generally have earned a poor name for quality and reliability, the BBC's broadcasts to the world are a shining exception.