Union workers for Hyundai Motor voted to strike on Thursday after being unable to reach a deal in wage talks.
The union and management agreed to resume negotiations over reforms to its pay structure, but the workers could go on strike as early as 14 September.
Hyundai is in the middle of restructuring its seniority-based pay system.
Strikes by its workers over wages occur almost yearly as the union seeks to raise monthly wages and bonuses.
This year would mark the fourth year of strike action if the two sides do not reach a deal.
Workers are asking for a 7.8% increase in their monthly basic wage, guaranteed job security until age 65 and bonuses worth 30% of the carmaker's net profit for last year.
The union represents more than 48,000 workers and about 78% of the 89% that voted supported the strike action.
Hyundai, together with affiliate Kia Motors, is the world's fifth largest carmaker.
The car giant's second-quarter net profit fell nearly 24% from a year ago, because of a stronger local currency and more competition at home and abroad.