France’s Foreign Minister Laurent Fabius identified the French national as Patrice Réal (49), who was working with a company on upgrading a hospital.
“He was killed with three shots,” an unnamed security official said.
The killing comes a week after police found seven Egyptian Christians shot dead execution-style on a beach outside Benghazi, which is home to several oil firms.
No one has claimed responsibility for the slaying of the Egyptians but residents said gunmen had looked for Christians in their neighborhood, suggesting radical Islamists might be behind it.
Most countries have closed their consulates in Benghazi and some foreign airlines have stopped flying there since the US ambassador and three other Americans were killed in an Islamist militant onslaught in September 2012.
An American schoolteacher was also killed by gunmen in December while he exercised in the city.
Three years after the revolution that ousted Muammar Gaddafi, Libya’s weak government and army are struggling to control brigades of former rebels and Islamist militias in a country awash with weapons.
Western diplomats worry that the violence in Benghazi will spill over to the capital, Tripoli.
In January, a British man and a New Zealand woman were shot execution-style on a beach 100 kilometers west of Tripoli
