The nuns were transferred to the village of Arsal, western Lebanon, earlier in the week.
It is unclear exactly who had held the nuns and why they had been released now.
However, reports in various media said the deal was brokered with the alNusra Front, one of the radical groups fighting against Syrian army.
Lebanon’s General Security Chief the head of Qatari intelligence were reported to have played a major role in the negotiations.
News of their release comes days after AFP reported that negotiators have lost contact with a group of nuns.
"It is very likely that they have been transferred to the region between Yabroud and the Lebanese border" nearby, a source told AFP.
The nuns were reported missing last year after radical militants seized the town, which is located on the edge of the rugged Qalamoun region, about 60 kilometers northeast of the capital.
Maaloula’s historic value lies in its ancient Christian presence and the fact that some of its residents still speak Aramaic, the language Jesus Christ is believed to have spoken.
SHI/SHI