* Talks set for hours ahead of union-set deadline
* Pressure mounts on government to reach a deal
JOHANNESBURG, Aug 11 (Reuters) - South African unions representing more than 1 million civil servants and the government plan wage talks on Thursday, hours before a union deadline to reach a deal that would avert a prolonged strike.
"We are optimistic that the government will come back to us with a significant offer. Our members want to avoid protracted strike action," Sizwe Pamla, a spokesman for the public sector union NEHAWU, said on Wednesday. The group is a part of the country's largest umbrella labour group, COSATU.
COSATU unions and other civil service labour groups staged a one-day strike on Tuesday, seeking an 8.6 percent pay rise, twice the current rate of inflation, and a 1,000 rand ($138) monthly housing allowance.
They threatened a prolonged strike they said would bring the government to a halt unless a deal is reached by Thursday.
The action increased pressure on President Jacob Zuma's government to prevent a repeat of a massive public sector strike three years ago that dented the economy and support for his predecessor, analysts said.
The government has offered 7 percent and 630 rand for housing, but analysts believe it is likely to raise its offer rather than risk a strike just before a policy-setting meeting next month of the ruling African National Congress.
Analysts expect the ANC, which has a longstanding alliance with organised labour, to give in to the unions' demands. Such a deal would make it hard to bring the budget deficit down from 6.7 percent of gross domestic product without spending cutbacks elsewhere.
Separately, South African auto workers seeking pay increases of more than triple the inflation rate went on an indefinite strike on Wednesday, hitting production. (Reporting by Jon Herskovitz and Peroshni Govender; Editing by Paul Taylor)