Hong Kong's unemployment rate rose to 4.6 percent in the March-May period, from 4.4 percent in February-April, the city's Census and Statistics Department said Thursday.

The underemployment rate, however, dropped from 2.1 percent to 2 percent in the March-May period.

Secretary for Labor and Welfare of the HKSAR government, Matthew Cheung, said the increased uncertainties in the external economic climate, coupled with the fluctuations in the local asset market, had affected general sentiment. Some employers were more cautious in hiring, resulting in a decrease in total employment.

"The labor supply is expected to pick up upon the entry of fresh graduates and school leavers into the labor market as summer holidays approach. The latest 0.9 percentage point increase of the unemployment rate for persons aged 15-24 from 10.2 percent to 11.1 percent suggested that pressure on youth unemployment is beginning to emerge," he said.

"Hong Kong's overall economic performance remains largely positive at present. Looking ahead, the trend of unemployment rate will hinge on the pace of economic growth, in particular whether the number of jobs to be created can absorb young job-seekers joining the labor force.

"The eurozone debt crisis and its contagion also pose uncertainties to the labor market. This will bring pressure on the unemployment rate in the near future. We will remain vigilant, continue to monitor the situation closely, and do whatever we can to assist job-seekers," he added.

Increases in the unemployment rate were mainly observed in real estate, professional and business services, arts, entertainment and recreation, import/export trade, and retail sectors. Drops in the underemployment rate were mainly seen in the foundation and superstructure, and social work activities sectors.

Total employment fell by about 7,100 to 3,483,300 while the labor force rose from 3,655,200 to 3,655,700. The number of unemployed people grew from 164,800 in February-April to 172,400 in March-May.

The number of underemployed people dropped by around 1,800 to 74,700.

The number of private-sector vacancies posted by the Labor Department rose 4.7 percent to 61,089 in May, and the number of successful placements rose 8.5 percent to 12,417.