TRIPOLI, July 1 (Reuters) - Four ministers in Libya's U.N.-backed government resigned on Friday in a setback for its efforts to extend its influence and unify rival factions.

The presidential council, the leadership body of the government, said it had accepted the resignations of the ministers of justice, reconciliation, finance, and economy and industry, but gave no reason for them.

All four are from the eastern region, where hardliners have so far not accepted the U.N.-backed government, supposed to replace two rival administrations that have been operating in Tripoli and the east.

Western powers hope the unity government can start to bring the main factions together to fight Islamic State, which has profited from the chaos to win control of some territory in the North African oil producer.

(Reporting by Ahmed Elumami; Writing by Patrick Markey; Editing by Kevin Liffey) ((pat.markey@thomsonreuters.com; +213-661-692993; Reuters Messaging: pat.markey.thomsonreuters.com@reuters.net))