The rocket hit the Burjesia residential and operations headquarters west of the city, they said. A security source said Exxon was preparing to evacuate some 20 foreign staff immediately.
Other companies operating at the site include Royal Dutch Shell PLC and Italian Eni SpA, oil officials said.
Moreover, a rocket landed near an Iraqi military base hosting US forces in the northern city of Mosul late on Tuesday, an Iraqi military statement said, the second such incident in two days.
The statement gave no immediate reports of casualties. It said the rocket fired was a short-range Katyusha missile, Reuters news agency reported.
Mosul’s military commander said the rocket landed in an open space causing no casualties or damage. He said it was fired from west Mosul, across the Tigris river, and was a “locally made” rocket, without elaborating.
MA/PR