Dame Marjorie Scardino - the first woman to head a FTSE 100 company - is to step down as chief executive of Penguin books and Financial Times owner Pearson.

Dame Marjorie's departure at the end of the year will leave just three female chief executives among London's top 100 public companies as she will be replaced by John Fallon, head of Pearson's international education arm.

The 65-year-old transformed Pearson when she joined as chief executive in 1997 from a diverse conglomerate, owning a range of unconnected businesses from Alton Towers to Thames Television, to a more focused "learning" company.

Announcing her departure, the American-born British citizen said: "It has been a privilege to be part of such a great company for a small part of its history."

Angela Ahrendts at fashion group Burberry, Cynthia Carroll at miner Anglo American and Alison Cooper of Imperial Tobacco will be the remaining female chief executives on the FTSE 100 Index.

The Government-commissioned Lord Davies review, published in February 2011, recommended that firms listed on the FTSE 100 Index should aim for a minimum of one in four female board members by 2015.

A voluntary code, developed in response to the Lord Davies review, was implemented in July 2011 to set out key principles of best practice for executive firms.

The number of women in the boardroom's of the UK's top companies increased in the past year, according to a progress update from the Department of Business, Innovation and Skills in July this year. Women now make up 16.7% of FTSE 100 Index, up from 12.5% at the time of the Lord Davies report, and 10.9% of FTSE 250 boards, up from 7.8%.

A graduate of Baylor University in Texas and the University of San Francisco School of Law, Dame Marjorie saw sales at Pearson triple to nearly £6 billion and profits grow more than three times to a record high of £942 million in 2011. However, the group recently saw sales rise 7% to £2.6 billion but underlying operating profits drop 10% to £188 million in the six months to June.

Mr Fallon, who is responsible for the group's education businesses outside the US, including in China, India and Brazil, said: "Marjorie's legacy is a company with a strong performance record, a deep commitment to its wider social purpose and a unique culture."

The Press Association, photo by irispengpeng