The average annual salary for workers in the private sector was 4.54 million yen last year, posting a decline for the fourth consecutive year, the National Tax Agency said Thursday.

The agency attributed the drop to an increase in lower-paid workers, such as part-timers, and a decrease in highly paid employees due to corporate restructuring efforts amid the sagging economy.

"What was particularly affected were bonuses, which were cut to reflect business performance," an official said.

Last year's annual salary on average was down 70,000 yen, or 1.5 percent, from the previous year, both the largest on record, according to the agency's survey on private-sector pay.

Of the average salary, 3.77 million yen was from monthly wages, down 1 percent from a year earlier, and 775,000 yen was from bonuses, down 4 percent.

The average annual salary for male workers was 5.58 million yen and for female workers 2.78 million yen.

Private-sector salaries amounted to 204.74 trillion yen last year, down 1.2 percent from the previous year, also a decline for the fourth year in a row.

Private-sector employees on the payroll numbered 45.09 million, compared with 44.93 million the year before. It was the first increase in three years.

Of them, there were 28.34 million male workers, down 0.2 percent, and 16.75 million female workers, up 1.2 percent.

The highest earners were workers in the chemical industry -- paid 5.73 million yen, followed by those from the financial, insurance and real estate industries at 5.64 million yen.