Pretoria's financial ties to West get a boost. Foreign capital is trickling back and debt has been rescheduled, but West is still cautious

Pretoria's frayed ties with Western investors are suddenly looking stronger again. Foreign capital is trickling back - enticed by an exchange-rate bonus and signs that the government has slowed the momentum of black political unrest. And late yesterday, Pretoria announced a second-stage repayment accord on South Africa's debts to Western creditor banks - easing a crisis that erupted when the banks refused to roll over repayments in mid-1985.

A return of large-scale foreign investment and credit facilities, indisensible for South Africa to resume its late-1970s strategy of expanding growth at home and financial links abroad, remains highly unlikely for the time being. Caution still seems the watchword for many Western banks; and divestment, a temptation for Western companies.

Two developments have officials and businesses here hoping that the worst of their crisis with the kings of Western capital may be over. One is the debt accord. The other is a demand-induced surge this month in the value of the ``financial rand'' - the discount-rate version of the South African currency available to foreign investors.

Once worth more than an American dollar, the undiscounted rand has sunk as low as 35 cents in the past year and a half, with the financial rand at barely half that figure. But this month, the financial rand has surged from about 24 cents to 30 cents. The ordinary rand has settled at about 48 cents.

Even the most optimistic of South African analysts expect the road back to be potholed and sinuous. The financial rand's advance, notes an economic expert, has been largely because of the ``attractive prospect of what amounts to half-price investment in areas like oil and mining.'' And the rand-dollar exchange has benefited from the weak dollar.

The debt-rescheduling accord - under which some $1.4 billion of the $13 billion in South African obligations due to private banks will be repaid in the next three years - is at best a first step toward reforging strong credit and investment lines with the West.

Analysts here see at least two prerequisites to such a rebound:

The domestic economy must forge ahead with its incipient recovery from its worst recession on record.

The government must make good on its hope to turn back twin challenges from left and right in a May 6 white national election, keep a lid on unrest, and bring credible black leaders into promised talks on ``power sharing'' at the national level.

The first challenge is likely to prove easier than the second. The domestic economy does seem resurgent. But there are potential hitches. Unemployment remains high among whites - and as high as 50 percent in some black urban areas. Inflation, already around 20 percent, shows signs of inching higher.

Yet more important seems the likelihood that any overall recouping of Pretoria's international economic links will require moves to reduce the political liability in foreign banks' and businesses' dealings with South Africa. On one score, the government has made progress, conveying a sense that a measure of stability has been restored after two years of escalating violence. Still, the authorities have yet to win credible black support for the official strategy of race-policy reform.

Yesterday's rescheduling accord, in this context, was an important yet partial victory. Successful Western bankers get that way by making shrewd dollars-and-cents judgments. No matter how they may feel about the politics of South Africa, the country's strong showing on last year's first-stage rescheduling commitments - and agreement on the second-stage repayment - stands in stark contrast to the recent debt-payment moratorium of some developing nations. With huge gold reserves, South Africa remains a relatively good credit risk.

Yet a political challenge remains. ``There are,'' declared moderate South African business leader Fred du Plessis some weeks ago, ``critical [political] choices to be made. A government that moves to the left will almost certainly alienate the right; but if, at the same time, it fails to win approval and support to its left, it is in danger of bleeding to death....'' Without a convincing move forward on reform, he reasons, any economic resurgence ``is likely to be somewhat short term and ephemeral....''

This report was written in conformity with South Africa's press restrictions.