The European Commission cleared Deutsche Telekom's purchase of Greek firm Hellenic Telecommunications Organization, known as OTE, a Dow Jones report said.
OTE provides fixed line communications services in Greece and Romania and mobile services in Bulgaria, Greece and Romania through its subsidiary Cosmote.
The Dow Jones report quoted the commission saying its investigation of the acquisition didn't uncover any competition concerns.
The report also quoted Deutsche Telekom CEO Rene Obermann saying that the decision is an important milestone towards strategic cooperation between the two companies.
Deutsche Telekom expects local antitrust bodies in southeast Europe, including Greece, to release their decisions in October.