The board of directors of Siemens approved a proposal to acquire 50% stake in Flender, which has a manufacturing facility at Kharagpur, West Bengal.According to a release issued by Siemens to the BSE today, the unit manufactures industrial gear boxes and related accessories."The other 50% stake is held by Flender AG, which was globally acquired by Siemens AG in August 2005. The new business of Flender will strengthen the company's automation and drives division, and will expand its drive technology portfolio by adding gear systems," the release added.