The number of employees working at private companies in Japan decreased last year for the first time in 50 years, the National Tax Administration Agency said in a report released Tuesday on the profile of the nation's salaried workers.

The agency said the amount of income earned by the nation's salaried workers last year also shrank, apparently the result of the prolonged economic slump that prompted many companies to downsize their payrolls and trim labor outlays.

According to a nationwide survey conducted by the tax agency, Japan had 44.98 million private-sector employees last year, down 1 percent from 1998.