Wage negotiations between POSCO Co. and its unionized workers have collapsed, the steelmaker's union said Saturday, warning it would go on an indefinite strike from early next month. POSCO and the union had been in negotiations over wages, but the two sides came unstuck over wage increases and other issues. The union said it will begin an indefinite strike from 7 p.m. on Nov. 2. The union had demanded a 7.1 percent increase in basic salary and a bonus worth 600 percent of basic salary. However, POSCO had offered a 2.5 percent increase in basic pay and a one-off payment of five million won ($3,770). Last month, unionized workers at POSCO held two rounds of partial strike after failing to narrow differences in wage negotiations.