Black bank tellers, government clerks and telephone operators have made their appearance over the past year in once lily white Rhodesian offices.

Their presence is part necessity, a kind of civilian equivalent of the massive Africanization which, because of the war's strain on limited white manpower, has turned Rhodesia's security forces into a two-thirds black operation.

It is also part of an atmosphere of hedging bets for the future reminiscent of the racial tokenism of the final pre-independence period of British and French colonial rule in black Africa nearly 20 years ago.

No one is hedging more resource-fully than the white business community which has looked askance at Prime Minister Ian Smith and his policies ever since he disregarded its advice and declared Rhodesia unilaterally independent of Britain in 1965.

Convinced that the economy is nearing collapse, many businessmen hope for a transfer of power to black majority government as part of an internal settlement between Smith and moderate African leaders, and the sooner the better.

They feel such a settlement - it it receives international acceptance - could open up foreign markets now closed off by the trading sanctions voted by the United Nations.

As proof of its goodwill, though cynics might call it self-interest, the business community recently launched ambitious training programs for blacks.

"We've been slack in the past, but now we want to help," a spokesman for local industrialists said. "We are becoming teachers."

Such a view contrasts with the official attitude typified by the government-controlled television, which rarely shows a black face or caters to the black majority.

Businessmen confide privately that they would have done much more long ago had it not been for government opposition.

Yet even this segment of white Rhodesians - who travel and try to understand the rest of the world - shows traces of the typical Rhodesian's insularity.

"They do not understand what even moderate African nationalists want for this country after black majority rule," a university professor said "much less the more radical changes advocated by the guerrillas doing the fighting."

Presumably the policies of a black majority government would drastically effect the lives of the whites who remain in the country. If nothing else, such a government could be expected to reorder government expenditure on education for blacks, which is roughly a tenth of that spent on whites.

Left unsaid by many enlightened whites is the implication that white economic power will continue to hold sway - and be a force for moderation - even after the blacks take over political control.

The Smith government is not wholly in tune with this segment of the 250,000-strong white community.

White business leaders insist they have pleaded with Smith to increase black wages only to have their advice rejected on the ground that he fears ultra-rightwing opposition.

Some economists wonder about the economy's much vaunted resilience, diversification and sophistication in light of a recent International Labor Organization study that showed white workers were paid 11 times more than blacks.

Even a moderate black government could well feel obliged to prove its credentials by boosting black wages substantially.

Any future political stability will also be affected by the need to provide employment for the estimated 60,000 young Africans entering the job market every year.

Some economists have estimated that the economy would have to return to its boom level of 7 percent annual growth as in the early '70s to achieve that goal.

There are other factors that enter the equation.

Pessimists fear that any black majority government sooner or later will be transformed into a frontline state in an armed struggle against South Africa. The economic repercussions would be disastrous.

Even without such doomsday predictions, whites were sobered recently by the publication of a report by Ian Hume, an economist with the locally based Whiteson Foundation.

In the smoothest of transitions to black rule, he foresaw minumum white flight, an investment boom capable of sustaining land reform and better wages for blacks, major foreign investment and foreign aid and the creation of 70,000 new jobs annually.

He estimated, however, that socialist reforms favored by one wing of the guerrillas fighting the Smith government, would lead to near total white exodus, an absence of meaningful foreign development aid or investment and reduction of one-half to two-thirds of black jobs.