None of the companies listed in the FTSE 100 appointed a women to be a full-time member of their board over the past year, a new report has revealed.

BoardWatch, which tracks the appointments of females to UK boards, found that the last woman to be made an executive director of a leading company in the UK was Tracy Robbins, who was named human resources director of InterContinental Hotels Group in August 2011.

Over the past two years, just four of the past 87 executives hired by Britain’s 100 biggest firms were women and none of these were hired over the past 12 months.

Overall, there are only 20 female executive directors employed by businesses listed in the share index, which includes supermarket giants Tesco and Sainsbury’s, as well as telecommunications firm Vodafone Group and Royal Bank of Scotland.

Jane Scott, UK head of the Professional Boards Forum, which compiled the data for BoardWatch, claimed that the figures were “a great cause for concern”.

She told The Times: “The pipeline in the executive world seems to be broken.”

The shortfall in female appointments comes despite recent efforts from the government to encourage large companies to hire more women.

In February 2011, Lord Davies of Abersoch published the Women on Boards report which urged FTSE 100 companies to ensure that at least a quarter of their directors were women within four years.

Although the proportion of female directors at Britain’s biggest companies has risen from 12.5 per cent to 16.7 per cent since the release of the report, many of these are only part-time or non-executive posts.

Data from recruitment consultancy Norman Broadbent shows that just 6.5 per cent of full-time executive roles are held by women, a rise of one per cent since February last year.

In an interview with MailOnline, Ms Scott did underline the fact that progress is being made to increase diversity in the workplace.

“We are now seeing a brighter spotlight directed towards the challenge of growing the pipeline of women senior executives and executive directors in UK businesses,” she said.

“All the companies we talk to are developing strategies to increase the ranks of senior women in their top executive teams as well as looking for gender balance and diversity in the boardroom.”