BEIJING—A second Chinese solar company has defaulted on a debt payment to investors, adding to the challenge Beijing faces in fixing its solar industry.

LDK Solar Co. said Tuesday that it missed a $23.8 million bond payment because of a "temporary cash-flow shortage." LDK said it reached a settlement with two bondholders to delay $16.6 million in payments but that it remained in discussions about the rest.

LDK...