BERLIN (Reuters) - Volkswagen's chief financial officer said in comments to investors seen by Reuters on Wednesday that the next step to making its German plants competitive was to improve productivity, increasing the number of cars produced per worker.

CFO Arno Antlitz, speaking to investors in New York on Tuesday, said that the cost-cutting deal struck with unions last December tackled the carmaker's problems of high labour costs and capacity underutilisation.

The deal was attached to clear and measurable milestones and new measures would be developed if goals were not met, Antlitz added, without specifying what the milestones were.

However, increasing productivity was the decisive third step to achieve cost reduction targets and create conditions in which the company could make further investments in plants, he added.

"We will only invest in competitive plants. Germany cannot be an exception," Antlitz said.