Austria faces period of uncertainty as Kreisky era ends

''Kreisky goes'' proclaimed the biggest headlines here Monday. This, as everyone anticipated, was the issue of Austria's general election on Sunday.

But behind the big black type, the reports reflected the uncertainty that will follow the departure of a man who was not only Austria's ''Mr. Stand Fast'' during a decade of consensus that benefited the economy but who was also a European politician of international stature.

It was the foreign press rather than the domestic news media that, after his defeat, most acknowledged Chancellor Bruno Kreisky's substantial role in world history: in post-World War II affairs, in efforts to mediate between Jew and Arab in the Mideast, in looking for areas of understanding behind international East-West tensions, and in seeking more aid for the world's backward South from the affluent and not overgenerous developed North.

''After the feast, the reckoning'' is very much Austria's mood after the Sunday vote that ended the absolute majority Kreisky and his Socialist Party had commanded since 1971 - and with it the ''Kreisky era.''

A keenly disappointed chancellor lost no time in ''putting on his hat'' and resigning office, as he had said he would. He said he plans to retire to his home in the Vienna woods or his villa on Majorca and to spend his time writing.

Mr. Kreisky was seeing Austria's President, Rudolf Kirchschlager, to tender his resignation as head of government and meeting with his party to consider the future and his own successor.

The Socialists chose Vice-Chancellor Alfred Sinowatz to head the efforts to form a coalition government.

The immediate question now is whether the coalition that replaces him will be ''big'' or ''small.''

Kreisky's party has to decide whether, for the time being, it will enter coalition with the conservative People's Party or the small (but potentially tune-calling) liberal-rightist Freedom Party. The Socialists lost five seats (from 95 to 90) in the National Council, or upper house of parliament. The People's Party gained 4 to total 81 seats, and the Freedom Party gained 1 seat to secure a total of 12.

The People's Party is willing to join a coalition, but only if opportunity for private sector investment is increased and curbs are put on the social welfare state engineered by the Socialists.

The Socialists are inclined toward a joint compromise program with the liberal Freedom Party, and the latter is ready. But few believe it could last long. If it did not, another election would not be far off.

Where the Kreisky party lost its edge is not yet quite clear. But it looks as though the newcomer ''greens'' (a pale shadow of West Germany's) took enough from the Socialists to make the difference even though they did not capture enough votes under Austria's proportional representation system to secure a single seat in parliament.

But what seems to have counted most against Kreisky is dissatisfaction on the part of ordinary, coalition-minded Austrians with a system that enables a party with just over 50 percent of the vote - which the Socialists had last time - to rule the roost so completely that the rest of the electorate in effect is disenfranchised.

So coalition could remain Austria's order of the day longer than the politicians now think.