Women’s networks from each of the four major companies launched a pilot scheme last year based in London to work in partnership with Girls Talk London, an organisation which aims to empower women to learn from others in senior roles in business.

The scheme was a big success and resulted in 18 of the girls graduating at a ceremony at Kings College London in 2016. Now all four companies have reiterated their commitment to the scheme in London, with BT launching an expansion in Birmingham.

The expansion of the scheme, known as ‘Step into STEM,’ is being celebrated tonight, Wednesday, 8 March, at an event at the BT Tower on International Women’s Day.

Schools who have students on the programme include: King’s Maths School, UCL Academy, Heathcote School, Woodford County High, City Academy Hackney and Highbury Fields School.

Over the past month, there have been 100 applications, which have been reviewed by Girls Talk London who also conducted interviews and an assessment centre with the candidates.

[Read more: What is International Women's Day?]

More than 30 school pupils have been selected and matched with a mentor from each of the businesses involved. The girls will receive one session a month with their mentor up until October, as well as a full week of work experience in July.

The scheme was initially a pilot, but now all four companies have big ambitions for the programme, and the hope is that it will be rolled out to other locations across the UK through further collaboration.

Ivelina Koleva, head of global cyber security commercial bids at BT, said: “Launching an expansion of the ‘Step into STEM’ programme speaks volumes of the drive and commitment of the Gender equality networks of BT, Ericsson, Vodafone and O2. There are so many STEM career opportunities for women to pursue and we are excited about the role we can play in continuing to inspire and support female school leavers who may be considering such a career. This year BT is piloting the scheme in Birmingham and we’re very keen to turn it into another success story.”

Jeni Mundy, Vodafone Group enterprise product management director, said: “A career in STEM can be hugely rewarding and stimulating, so we are proud to be part of this scheme to both inform and encourage more girls to aim for roles in this sector. This year we will be providing eight mentors for girls in London to offer help and advice to shape their future career in the technology field. We believe we should be many, not few.”

Federica Mills, head of sourcing UK and chairwoman of the UK Women Network at Ericsson, said: “I am proud to lead the Step into STEM Mentoring Programme for Ericsson for the second consecutive year and to have the opportunity to once again offer mentorship and guidance to more young women at such an important stage of their lives. This is a brilliant and concrete example of Ericsson’s commitment to addressing the gender imbalance and attracting female talent in the ICT industry. Working together, we will have more young women pursuing studies in STEM subjects and considering careers in ICT.”

Brendan O’Reilly, chief network officer at O2, said: “2016’s step into STEM programme was hugely successful and we’re looking forward to building on that success again this year. As digital technology becomes ever more important in today’s society, the opportunities for a career in STEM will only increase.”