SEOUL, March 5 (Reuters) - South Korea's finance minister said on Monday that General Motors Korea' creditors and its labor union should share the burden of improving the loss-making operation.

"The unions and creditors should together share the burden, and (restructuring measures) should not be temporary but sustainable," Kim Dong-yeon told reporters.

GM Korea announced last month it would shut down a factory in Gunsan, southwest of Seoul, and that it was mulling the fate of its three remaining plants in South Korea. (Reporting by Shin-Hyung Lee; Writing by Cynthia Kim; Editing by Edwina Gibbs)