FRANKFURT -- German supplier Continental tried to buy Siemens' stake in lighting group Osram in the summer but was turned down, business monthly Manager Magazin reported, citing company sources.
The magazine said the 50 euros-per-share offer for the 17 percent stake was the last chance to keep Osram as a predominantly German company.
Continental, Osram and Siemens declined to comment on the magazine report.
Osram is a market leader in automotive lighting, and is developing new products including smart LED headlights and special laser diodes for Lidar (light detection and range scanning) technology needed for sensor systems in self-driving cars.
Osram has talked to Sanan Optoelectronics about a possible takeover by or cooperation with the Chinese company, and has also been reported to be in the sights of Chinese financial investor GSR Go Scale Capital.
A spate of takeovers by Chinese buyers has prompted the German government to consider whether it needs to do more to protect key technologies.
Osram shares traded in a range of 42.58 to 51 euros per share between June and August. The shares were trading up 0.1 percent at 54.11 euros on Thursday.