HONG KONG - The estimated number of Hong Kong's residential mortgage loans in negative equity increased from 48 cases at the end of June to 1,653 cases at the end of September, the Monetary Authority said on Friday.

Most negative-equity cases were related to mortgage loans with a loan-to-value ratio at 90 percent or above, including staff housing loans and loans under the mortgage-insurance program, the statement said.

The aggregate value in negative equity rose to HK$4.148 billion at the end of September compared with HK$58 million at the end of June, representing 0.5 percent of the total amount of outstanding mortgage loans at the end of September.

The unsecured portion of these loans increased to around HK$165 million from HK$18 million in the third quarter.