South Korea\'s largest carmaker Hyundai Motor Co. said Monday that its sales jumped 29.1 percent in August from a year earlier despite partial strikes that cut the carmaker\'s vehicle output. Hyundai sold 381,429 vehicles in August, compared with 295,449 units in the same month in 2012, the company said in a statement. For the first eight months, Hyundai sold more than 3.13 million nits, up 11.5 percent from a year ago, according to Hyundai. The strong sales performance came despite Hyundai\'s 46,000 unionized workers walking off the job for several hours. It was their seventh partial strike since August to demand a wage hike and other fringe benefits. Still, leaders of the union and management resumed negotiations on Monday to narrow their differences over the union\'s demands. They include a special bonus amounting to 30 percent of the company\'s net profit last year, which was 9 trillion won (US$8 billion). The union is also asking for a hike of 130,000 won in basic pay and a one-year extension of the retirement age to 61. In addition, they want an allowance of 10 million won each for workers\' children who choose to seek employment instead of going to college. The work stoppages in recent weeks cost the carmaker 795.7 billion won in lost production, according to Hyundai. Also Monday, about 30,000 union members of Kia Motors Corp. staged a partial strike to press for a similar pay hike and other fringe benefits. Kia is a smaller sister company of Hyundai. Hyundai and Kia, which together form the world\'s fifth-largest automaker, have long been plagued by labor disputes. Hyundai\'s workers have downed their tools every year since 1986 except for 1994, 2009, 2010 and 2011. A strike last year cost the carmaker some 1.7 trillion won in lost production. Kia\'s union has gone on strike every year since 1999 except in 2010 and 2011, when the country\'s No. 2 carmaker was taken over by Hyundai Motor Co. following the 1997-98 Asian financial crisis.