Hellenic Railways Organisation (OSE), founded in 1971 and headquartered in Athens, was the wholly state-owned manager of Greece's national rail infrastructure, Athens Metro Line 4 Phase A (Alsos Veikou–Evangelismos) · News
Hellenic Railways Organisation (OSE), founded in 1971 and headquartered in Athens, was the wholly state-owned manager of Greece's national rail infrastructure, responsible for track, signalling, electrification, and rail real estate. Following the August 2025 corporate reform, infrastructure operations transitioned to the new Greek Railways entity under the Ministry of Infrastructure.