Helsinki  - Nokia, the world's largest maker of mobile phones, Wednesday said it planned to concentrate its mobile research and development to fewer sites in Finland and introduce temporary layoffs to counter lower demand.

The site for mobile research and development in the city of Jyvaskyla, was to be closed by the end of 2009, impacting some 320 employees, the group said.

Research and development sites were to remain in Tampere, Oulu, Salo and the greater Helsinki area.

In a related move, Nokia was to reduce production at its Salo plant by introducing temporary lay-offs on a rotational basis to adjust production with market demand.

The temporary lay-offs would affect about 20-30 per cent of the some 2,500 employees in Salo during each phase, Nokia said, adding talks were to commence with unions.

Last month, Nokia reported a 19-per-cent drop in sales and a sharp drop in operating profit for the fourth quarter of 2008.

Chief Executive Olli-Pekka Kallasvuo cited factors such as "weaker consumer confidence, currency volatility" and credit tightness. (dpa)