Jumblatt himself appears to be allied with the opposition led by Hezbollah, Voice of America reports. But it is unclear how many in his parliamentary bloc will join him.
Lebanon has been in crisis since opposition ministers withdrew from the governing coalition, leaving Saad Hariri unable to continue as prime minister. Hezbollah is expected to support Omar Karami.
Karami was prime minister in 2005 when his predecessor, Rafiq Hariri, Saad's father, was killed by a massive car bomb. He was forced to resign soon afterward.
Talks trying to put together a government are expected to begin Monday, unless they are postponed again. Hezbollah would need at least 65 members of Parliament in its coalition to return Karami to the prime minister's office.
Hezbollah precipitated the political crisis because Hariri decided to push forward with a U.N. special tribunal investigating his father's death. Jumblatt made the opposite decision after his father was assassinated in 1977, CNN said, deciding that working with the groups he suspected of killing his father was better for the Druse community.