South African Labor Minister Fanie Botha said today that the government will propose legislation next week to legalize black labor unions. The move would be the first step in eliminating racially discriminatory labor practices in South Africa's apartheid system.

At a Cape Town press conference, Botha, a reform-leaning minister, said the government had accepted "in principle" all the recommendations of 14-member multiracial commission that made its report public yesterday.

The commission's report represents a significant departure from the government's racially segregated labor policy, a cornerstone of its political philosophy of apartheid, according to many government critics.

The leading white opposition newspaper the Rand Daily Mail commented that report offers hope for "a huge and exciting transformation of industrial relations in South Africa."

Anti-government blacks were lukewarm in their reaction. One black professional organization warned that until the recommendations were enacted by the all-white parliament, they would remain "one of the perennial breakthroughs that never materialize."

Besides recommending the legalization of black labor unions, the multiracial commission's report suggested that the government allow multiracial unions, full trade union rights even for migrant workers, the opening of union apprenticeship training programs to all races, equal pay for equal work and the scrapping of laws that reserve certain jobs for whites, except in the mining industry.

The government's implimentation of the commission's recommendation will be watched carefully by its critics as "a vital test that test that the ruling National Party will give more than a cosmetic content to its claim to be moving away from (racial) discrimination," according to an antigovernment academic, Willem Kleynhans.

Legislative action on recommendations comes at a time when the South African government faces a potentially explosive political problem in the rising unemployment figures for both whites and blacks.Urban black unemployment is estimated at between 16 and 22 percent.

Despite this unemployment, the economy faces a major shortage of skilled manpower that is largely the consequence of decades of refusing to train blacks as skilled workers because of discrimination. In the past, white immigrants supplied most of the required skilled labor, but that source has dried up recently with the drop in white immigration due to political uncertainy here.

Many of the report's recommendations are a response to pleas of business leaders who have been calling for the lifting of discriminatory laws that hinder black advancement and often make businesses uneconomic.

But the business community's requests in the past have often been outweighed in the government's mind by the pressure from organized white labor, which fears losing its job security and its privileged position.

Unionized white workers traditionally have been a backbone of political support for the National Party since it cames to power in 1948, in large part because of organized backing from white miners. The support of white labor unions now is crucial to the government's successful implementation of the commission's recommendations.

Aware of this, Botha today promised that all changes in the labor field would be implemented with caution and care and only gradually. Botha acknowledged some opposition to the government's proposals but said he believed this was only among a minority of white workers.

An example of that opposition came today from a union chief in the iron and steel industry, Wessel Borman. He said, "In my opinion the report advocates total labor integration, which in turn amounts to social integration of all the races. If this is accepted by the government, one wonders how long it will take before other legislation very near and dear to the heart of the whites will disappear."

Significantly, the report avoided any suggestion about the controversial laws that reserve jobs for whites in the mining industry, which is dominated by a very conservative white union. Three months ago, the miners caused disruption in the mines with wildcat strikes opposing the advancement of black workers at one mine.

Black labor leaders said little about the proposal for legalizing black unions. Up to now, these black union leaders have operated as unofficial ne gotiators with management for their members, lacking the legally enforceable negotiating rights that white union leaders have.

The black union chiefs are apprehensive that the established white unions, with ready finance and organized administrations, will be able to unionize the black workers more efficiently than they can with their less lavish resources, thus keeping the black unions under white control.