The announcement comes after weeks of international pressure and protests in the Lebanese capital Beirut.
Up to 5,000 Syrian troops will leave outposts overlooking Beirut, but the fate of the 14,000-strong Syrian garrison has been deferred.
France, Germany and the US have called for an immediate withdrawal of troops.
But a joint Syrian-Lebanese statement said the “size and length of stay of Syrian forces in Bekaa” would be agreed a month after the initial redeployment.
