The two companies are locked in a dispute over smartphone patent royalties.
Nokia has started a $100 million fund to invest in companies working on connecting cars.
Finnish telecommunication gear maker Nokia reported higher-than-expected quarterly earnings.
Nokia has accused HTC of patent infringement and seeks financial compensation.
Workers massed outside the factory gates in the industrial city of Dongguan in China.
An overwhelming majority of shareholders agreed to the sale at a meeting in Helsinki.