Gross average salary declined 2.8% to RON2,328, the data showed.
Staff in the oil and gas sectors received the biggest paychecks in May, of RON5,512, the data showed.
At the opposite end, hotel and restaurant employees received the lowest monthly salaries, of RON959.
In May compared with the year-earlier month, Romanian average net salary rose 4.4% in nominal terms. (EUR1=RON4.3897)