Ahead of International Women's Day on March 8, 2008, a global study of sixty-three nations has revealed women across all industries and age groups are being paid on average 16 per cent less than men.
ACTU president Sharan Burrow said the International Trade Union Confederation (ITUC) Report on Pay Equity revealed the extent of discrimination women still faced around the globe.
"In this day and age the gap is appalling," Burrow said.
"In reality it is probably even wider than the figures suggest because developing countries don't keep national records, nor do hundreds of millions of women working in informal and unprotected jobs appear in any records.
"While education is often touted as the key to closing the gap, the study shows it's educated women who are experiencing the widest pay gap of all with their male counterparts."
The ACTU president said unions are working hard in Australia and in other countries to bridge the pay divide by educating governments, employers and the public.
However it is collective bargaining which remains the best means of closing the pay equity gap, the ACTU said.
Professional women in the science, engineering and technology sector do not receive equal pay for equal work, according to a survey by the Association of Professional Engineers, Scientists and Managers Australia (APESMA), which found more than 25 per cent of professional women reported a pay disparity with their male counterparts.
For women with business qualifications and those in senior management positions, the figure was much higher at over 40 percent.
APESMA national women's co-ordinator, Erin Wood said female professionals are not getting any closer to bridging the pay divide.
"The trend over the past seven years has not changed. Our research has consistently shown that professional women do not believe they are being equally compensated for the work they do," Wood said.
"OECD reports substantiate our findings. The recent Gender Gap Index, ranked Australia 45th out of 115 OECD nations on wage equality for similar work.
"It is very disappointing that this problem remains despite an acute skills shortage and high demand for technology professionals."
According to a recent Computerworld salary survey, which covered 400 IT professionals in Australia, the average salary for a male IT professional is $98,684 compared to $81,906 for a female.
Currently in Australia women make up only 20 percent of the ICT sector.
Gartner analyst, Diane Morello, said the poor pay figures are symbolic of the obstacles and roadblocks that are sending women away from IT in droves.