Gross average salary decreased by 3.2% to RON2,226, the data showed.
Staff in the financial sector fell by 22.6% to 25.6% on the month in May, while Romanians working in insurance received by 10% to 14% less money compared with the previous month.
At the opposite end, employees in the oil equipment field were paid by 7.5% more in May, the data showed.
In May compared with the year-earlier month, Romanian average net salary rose 5.3% in nominal terms. (EUR1=RON4.442)