BEIJING—A Chinese real estate developer warned Friday it might fail to pay off a $400 million bond due next week, adding to financial strains in an industry that is struggling to avoid defaults on billions of dollars of debt. Kaisa Group Holdings Ltd., headquartered in Hong Kong, said it tried to renegotiate the debt due Tuesday but too few bondholders agreed to the unspecified terms. “There is no guarantee that the company will be able to meet the repayment obligations,” said a Kaisa statement released through the Hong Kong Stock Exchange. It did not say if there was a grace period before it would be declared in default, which can trigger requirements to repay other debts immediately. Some Chinese developers are struggling to reduce debt after regulators tightened limits last year on their use of borrowed money, which is fueling fears about possible defaults and turmoil in financial markets. Investors …