South Africa's black mineworkers' union, tacitly conceding it lacks the strength to win a labor showdown in the country's essential gold and coal mines, tonight called off its sputtering strike against three mining companies.

Leaders of the National Union of Mineworkers characterized the move as a temporary suspension of the two-day walkout while they seek a court order barring the companies from firing striking workers. But analysts said the union appeared to be cutting its losses and was unlikely to resume the strike after the court ruling, which could take a week or longer.

The move brings to at least a temporary conclusion a strike that threatened to set off yet another round of violence in this white-ruled country, where at least 675 blacks have been killed during the past year. Although the situation in at least four mines remains explosive, the move may mark the first break in what has been a rising spiral of violence in the six weeks since the government decreed a state of emergency to quell the unrest.

[Meanwhile, the governor of South Africa's central bank, Gerhard de Kock, on an emergency mission to western financial capitals, acknowledged that international economic support would depend on the country's progress toward political change.]

The strike's suspension leaves uncertain the fate of more than 7,000 miners who face dismissal for participating in the walkout. The union said it had received assurances from the companies that they would not evict workers from mine property, and union general secretary Cyril Ramaphosa said he believed most of the miners would be allowed to resume work.

But the strike's suspension appeared to leave management with a free hand to dismiss strike leaders and other identified participants, and it may set back efforts to organize workers at the three companies where union membership has been lowest.

Spokesmen for the two companies most affected by the walkout refused to comment tonight. But one official, speaking not for attribution, said his company was "encouraged to learn the union has decided to call off the strike. It sounds like a healthy development."

Union spokeswoman Manoko Nchwe denied that the strike's halt was an admission of defeat. "The mining companies partly broke our strike and partly caught us unawares," she said. "But it's also a victory for us because it has shown the determination of our members in spite of all kinds of intimidation."

The halt may defuse increasingly volatile tensions at several mines that led to violence and one reported death today. Workers at the Deelkraal gold mine, west of Johannesburg, said a miner was struck by a police van and died during a confrontation this morning in which tear gas, rubber bullets and plastic whips were used to break up a crowd of strikers who had gathered outside the racially segregated dormitories where most black workers live.

Helene Mendes, spokeswoman for Gold Fields, owner of the mine, confirmed that an incident occurred but said the police acted after some union members attempted to intimidate other workers into joining the walkout. She was unable to confirm or deny the reported fatality, saying company officials were still investigating the matter.

Violence also was reported today at Transvaal Navigation Collieries, a coal mine owned by Gencor. Workers there said police discharged tear gas and fired rubber bullets outside a black hostel on company property. A company spokesman could not be reached for comment.

Deelkraal officials gave notice to 5,000 miners today that they were being fired for failing to report to work for two consecutive days. Workers said the mine's white hostel manager told them over a loudspeaker that they would be issued back pay Wednesday morning and would be required to leave the mine premises by 5:30 p.m. Officials at three Gencor mines, the Marievale gold mine and Transvaal Navigation and Blinkpan coal mines, said they had begun "disciplinary hearings" for more than 2,000 workers to determine whether they, too, should be fired. There were unconfirmed reports that several hundred Marievale miners were dismissed later today.

At least 35 persons have been arrested and two dozen injured since the strike began. Gencor also confirmed today that 87 union members whom it characterized as "intimidators" had been dismissed at its Beatrix gold mine in the Orange Free State.

The strike, which began two nights ago, was troubled from its inception. Union leaders knew they were striking at companies where support for the three-year-old union was weakest.

The two major mining houses where the union has most of its members had settled last week after last-minute negotiations. But two of the holdouts, Gold Fields and Anglo Vaal, offered only minor increases in vacation pay over their previous wage offer, and a third, Gencor, refused to offer any increase.

The union had targeted seven mines with a total of 70,000 miners, but workers at four of those mines refused to walk out. Workers at three other mines staged sympathy strikes, however.

Management and union spokesmen gave widely differing estimates of the number of workers on strike, with the union claiming 28,000 strikers and management putting the figure at 14,000. Each side also accused the other of using strong-arm tactics to force workers to accede to their demands. Because journalists were barred from mine property, there has been no independent evaluation of each side's claims.

One independent analyst, Prof. Eddie Webster of the industrial sociology department of the University of Witswatersrand here, called the strike "a draw." He said the fact that the young union had been able to wrest improved wage offers from three major mining firms showed its growing power.

The most severe violence reported today was around Cape Town and East London. Police clashed with stone-throwing mobs in several Cape Town townships, where at least 30 people have died in the past week.

One young black man was shot to death by police outside a school late last night at a school ground. Tonight, officials closed a major highway linking the city to its international airport after protesters blocked the road with burning tires and oil drums.

In Duncan Village, outside East London, another black man died today while allegedly participating in a gasoline-bomb attack on a police vehicle.