UPDATE 1-Serbia awards Belgrade airport concession to France's Vinci

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BELGRADE, Jan 6 (Reuters) - Serbia awarded a 25-year concession to run Belgrade airport Nikola Tesla to French construction and engineering group Vinci, which offered to pay 501 million euros ($603 million), President Aleksandar Vucic said on Saturday.

Vinci, Europe's biggest construction and concessions company, pledged to invest another 732 million euros over the 25 years, Vucic said.

He added Vinci had committed to keep all employees currently working at the airport.

Traffic at Belgrade airport has increased since 2013 when Abu Dhabis Etihad bought a 49 percent stake in indebted flag carrier JAT, rebranding it as Air Serbia and introducing new routes.

Once closed to international air traffic during a decade of war and sanctions under late Serbian strongman Slobodan Milosevic, the number of passengers using the airport hit five million in December.

Belgrade airport's CEO told a local news agency in December he expected profit to rise to 29 million euros in 2017 from 26 million euro a year earlier.

The government holds a 83.1 percent stake in Belgrade airport, while small shareholders own the remaining shares.

($1 = 0.8314 euros) (Reporting by Ivana Sekularac; Editing by Mark Potter)