SEOUL, May 15 : Samsung Electronics' South Korean labour union said on Friday it remained committed to a planned strike starting next week, even after the company proposed resuming pay talks without conditions, sending shares down as much as 5.9 per cent. Government-mediated negotiations between the union and the company over pay and bonus schemes collapsed this week, heightening concerns about a strike at the world's biggest memory chipmaker. The union on Friday said it was willing to hold new