BERLIN (Reuters) - German train drivers will stage a nationwide strike for the second time this week in a drawn-out dispute over pay and conditions with state-owned rail operator Deutsche Bahn, union GDL said on Friday.

The strike by the drivers' union is due to start at 3pm on Friday for freight traffic and at 2am on Saturday for passenger trains. The walkout, which comes as the school holidays start in many of Germany's federal states, is due to end on Monday at 4am.

GDL is seeking a 5 per cent pay rise for drivers and a shortening of their working week to 37 hours from 39 hours. The union also wants a mandate to negotiate for train guards and other personnel, something Deutsche Bahn has rejected.

The company wants to halt talks until the government passes a law which would mean a settlement with the biggest union in a firm would apply to all workers in that firm. GDL, which is not the biggest union within Deutsche Bahn, opposes such reforms.

On Wednesday and Thursday, train drivers already staged a 14-hour strike for passenger trains, causing major traffic disruptions as people were forced to use buses, cars and planes.