Nokia Siemens Networks says it has started talks with employees to cut 400 jobs in Finland as part of global plans to streamline operations.

The wireless network group announced last year it will slash 17,000 jobs worldwide — almost one quarter of its work force — to cut annual costs by €1 billion ($1.3 billion) by the end of 2013.

The joint venture between Finland's Nokia Corp. and Siemens AG of Germany has struggled to make a profit amid stiff competition in the global market for network infrastructure, the technology and services needed to run mobile and fixed-line networks.

Based in Espoo, near Helsinki, the company has operations in 150 countries. It employs 6,200 people in Finland.

Nokia shares were up 5 percent at 2.28 euros ($2.94) in Helsinki afternoon trading.