After a steep rise in April, the number of online job ads was unchanged in May, according to The Conference Board's measure of online job ads released today.

The number of online job ads was approximately 4.15 million, unchanged from April.

"After the large 223,000 April increase in online advertised vacancies that kicked off the spring hiring season, employers essentially held steady in May," said June Shelp, VP at The Conference Board.

However, some occupations posted gains in advertised job vacancies while others posted losses. Computer and mathematical science occupations posted the largest May gain with online job ads rising by 18,100 to 567,600.