Porsche, who are leaving the championship at the end of the season, also won the manufacturers' crown for the third year in a row.
Toyota won the race with Japan's Kazuki Nakajima, Britain's Anthony Davidson and Swiss racer Sebastien Buemi.
Le Mans 24 Hours winner Hartley, who also won the world championship in 2015 with Bernhard and Australian Mark Webber, is set to complete the Formula One season with Toro Rosso after making his debut at last month's U.S. Grand Prix.
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He also looks likely to be confirmed for 2018 with French rookie Pierre Gasly.
(Reporting by Alan Baldwin in London, editing by Amlan Chakraborty)
