Companies are to be urged to increase the number of women they have on their boards in the next two years or face Government quotas.
Former trade minister Lord Davies of Abersoch is expected to call today for a fifth of FTSE 350 board members to be women by 2013, rising to a quarter by 2015.
He will publish recommendations to the Government on how to increase the number of women on the boards of UK companies, but will stop short of calling for quotas to be introduced unless the voluntary measures fail, after finding a lack of support for the measure.
Head-hunters and shareholders will be expected to sign up to a new code of conduct, and chairmen will be urged to be more adventurous when appointing non-executive directors, with head-hunting agencies asked to provide more diverse shortlists.
Lord Davies is also expected to call for more women to be promoted to executive committees to ensure there is a larger pool of talent from which female non-executive directors could be recruited.
Women account for only 12.5% of directors of FTSE 100 firms, and based on current trends it is thought that it will take 70 years before women hold half of all posts at blue-chip companies.
The Progressive Building Society's Darina Armstrong is one of few female chief executives of Northern Ireland's top companies.
Other measures expected to be put forward include encouraging companies to publish their own targets on appointing women.
Lord Davies, the former boss of Standard Charter Bank, found little support for imposing quotas, with just 11% of respondents backing the idea.
Ruth Spellman, chief executive of the Chartered Management Institute, said: "News that companies will not be forced to promote female workers to the boardroom by quota will be widely welcomed by nervous businesses.
"However, a concerted effort still needs to be made to use female talent, otherwise companies will be missing out on a vast array of talent at their disposal."