Semiconductor equipment company Aixtron says the German government has re-opened its review of a takeover bid by China's Fujian Grand Chip.

Aixtron said in a statement Monday that the company learned on Friday that Germany's Ministry of Economics and Energy had withdrawn its clearance certificate for the 670 million euro ($737 million) deal.

Ministry spokeswoman Katharina Dubel confirmed the withdrawal but said she could not provide further information.

Aixtron, based in Herzogenrath, makes equipment used in manufacturing semiconductor chips. The takeover has raised concerns about Chinese efforts to acquire foreign technology and move it to China. Aixtron says its headquarters, research and development operations and existing technology will remain at its current sites.