Women are still hugely outnumbered by men in senior academic posts in the UK's universities, figures reveal.
More females than males are applying for university
There are almost six full-time male professors for every female professor, data on 2005-06 from the Higher Education Statistics Agency shows.
And of the senior lecturers and researchers working in universities, less than a third (30.8%) were women.
The University and College Union said institutions must act to ensure women are not stopped from reaching the top.
Overall the proportion of full-time female academic staff in UK universities rose slightly from 36.1% in 2004-05 to 36.6% in 2005-06.
Full-time female academics accounted for 41.8% of staff members at lecturer, researcher and other grades.
Although there had been a small increase (0.7%) in the proportion of females at professor and also at senior lecturer/researcher level (0.8%) since 2004-05, at other grades the gender split remained almost static.
And unusually, the number of women academics generally working part-time was only slightly higher than the number of men doing so, with around 3,090 (or about 6%) more women than men working part-time out of a total of 53,465.
But the gender gap emerges almost as strikingly at the most senior level among part-time academics, with nearly four-and-a-half times as many part-time male professors as female professors.
However for the past decade, more women than men have been attending university as students.
According to the latest figures, some 56% of those applying to university this year are women.
Joint general secretary of the University and College Union, Sally Hunt, said with ever-increasing numbers of women in the profession, there was no reason why more should not be in the top jobs.
Fair, open and transparent recruitment and promotion procedures were in everyone's interest, she said.
"What is equally important for the future is that institutions act to ensure equality of opportunity at every point so that women who are at the start of their academic career will face fewer obstacles in getting to the top than those who came before them.
"Women want equality now, rather than to wait until their daughters and granddaughters start work."
A spokesman for Universities UK, the vice-chancellors' body, said: "Universities are committed to providing equal opportunity in academia, which is why Universities UK established and continues to support the Equality Challenge Unit in taking such issues forward.
"The higher education sector has made substantial progress in recent years, but we are not complacent and recognise that there is always more that can be done.
"Redressing gender imbalances in academia, such as at senior level, is a long-term goal for the sector."
The Equality Challenge Unit said the fact there had been only small increases in female academic staff at a senior level was "very worrying".
Policy adviser Saheema Rawat said the unit was committed to addressing such issues, for example by looking at systems that promoted flexible working.
Chief executive of University and Colleges Employers Association Jocelyn Prudence said: "Good progress is being made across the sector with an increase in the proportion of females in senior academic roles and this is set to continue, but we recognise there is still more to do.
"The proportion of female professors has more than doubled in the last 10 years with improved promotion opportunities."
The HESA figures also showed that 10.7% of academic staff who chose to state their ethnic background were from an ethnic minority.
Overall the number of academics employed in UK universities rose 4,220 to 164,875 in 2005-06.
Just over two thirds of these (67.6%) of these were employed full-time.