Jan 9 (Reuters) - An earthquake with a magnitude of 5.4 was registered in northwestern Greece late on Sunday, with no immediate reports of injuries or damage, the country"s Geodynamic Institute said. The German Research Center for Geosciences (GFZ) earlier reported the tremor as having a magnitude of 5.8. "We don"t have reports for injuries or damages," a fire brigade official told Reuters. The Greek Geodynamic Institute said the quake struck at a depth of 14 km near the town of Florina.