The number of women directors in FTSE 100 firms has risen by 20 per cent over the past year to top 100 for the first time, according to annual figures compiled by the Cranfield School of Management.
Both AstraZeneca and M&S have four female directors each, representing a third of their boards. But while nine FTSE 100 companies have up to 30 per cent female representation on the board, 32 have no women on the board at all.
Marjorie Scardino of Pearson Group remains the only female CEO in the FTSE 100.
Accouncing the results of the survey in London, Trade and Industry Secretary Patricia Hewitt pointed out that the figures meant that only one in 12 FTSE 100 directors are women.
"That's not representative of their staff or their customers," she said.
"It is obviously good news that more boards are taking on female directors and drawing on the pool of talent available to them, but this report shows that there is still much more to be done."
"Research shows that companies with a good mix at the top have better corporate governance records, and tend to be at the top in terms of market capitalisation," Hewitt added.
Dr Val Singh, co-author of the report, said: "The increase of all these statistics is encouraging, but there is still much to do to identify and deal with the barriers for women in middle management, the next generation of women business leaders.
"So many companies seem surprised that high-flying women leave or stagnate in mid-career."