UPDATE 2-Hyundai Motor says working to resume Chinese production

* China factories suspended over past week - Hyundai

* Hyundai says to resume production as soon as parts arrive

* Shares fall to lowest since April 20

* S.Korean firms facing Chinese backlash (Recasts with Hyundai to resume production)

SEOUL, Aug 30 (Reuters) - Hyundai Motor said on Wednesday it would resume production in China as soon as the supply of parts resumed, after the South Korean automaker suspended production at its four Chinese factories last week due to supply disruption.

Hyundai's joint venture with China's BAIC Motor Corp Ltd had stopped production after a fuel-tank components supplier refused to provide parts due to non-payment, Hyundai said in a regulatory filing.

Hyundai shares skidded to their lowest level in more than four months on Wednesday, falling as much as 3.8 percent to their lowest since April 20.

Hyundai's Chinese business is grappling with a sales slump linked to diplomatic tensions between Seoul and Beijing. It was scheduled to start operations at a fifth factory in China this month.

South Korean firms are weathering a Chinese backlash over Seoul's decision to deploy a U.S. missile defense system to counter threats from nuclear-armed North Korea. China says the system poses a threat to its national security.

Hyundai Motor's sales from its Chinese factories fell 64 percent to 105,000 vehicles in April-June alone. ($1 = 1,122.0000 won) (Reporting by Hyunjoo Jin; Additional reporting by Joyce Lee,; Editing by Stephen Coates)