Two of Spain's largest companies will announce plans to expand their operations in London later today (30 March), just a day after Britain formally began the process of leaving the European Union after 44 years.

Telefónica, which owns British mobile network O2, and infrastructure group Ferrovial will unveil their commitments at an event organised by the Mayor of London's International Business Programme, held to promote greater links between London and Madrid.

The former, one of the largest telecoms operators in the world, will disclose plans to develop a new facility in Haringey, north London, through Wayra UK, which is part of Telefónica Open Future.

The project, which is backed by the Greater London Authority and the local council, aims to help entrepreneurs in outer London pursue their start-up ideas. Each year it will support approximately 10 digital start-ups outside of the capital's traditional tech hubs.

"London is always a reference, a mirror in which we can look at and learn on how to make business with an innovative spirit," Javier Placer, chief executive of Telefónica Open Future, will say.

Meanwhile, alongside with the GLA, University College London and Future Cities Catapult, Madrid-based Ferrovial will announce a programme aimed at improving day-to-day recycling in flats and multiple occupancy houses.

"These announcements demonstrate that, despite Brexit, business leaders in Europe realise that London will remain a key partner in business, investment, talent, ideas and friendship," the Mayor of London, Sadiq Khan, is expected to say.

"Our city was the only region in England to vote to remain in the EU, it is still the best place in the world to do business and our collaboration with other major European cities will not cease."

News of the investments comes barely 24 after Prime Minister Theresa May triggered Article 50 of the Lisbon Treaty, as Brexit began in its earnest just over nine months since last June's historic referendum.

While the PM added Britain will seek to retain a "deep and special" partnership with the EU, over the next two years there will be fraught negotiations between Britain and the remaining 27 states as they attempt to hammer out a new formal relationship, avoiding the metaphorical "cliff edge Brexit".

May also admitted that the UK will lose influence on the rules governing the European economy.

"We understand that there will be consequences for the UK of leaving the EU. We know that we will lose influence over the rules that affect the European economy," the Conservative premier told the House of Commons.

"We know that UK companies that trade with the EU will have to align with rules agreed by institutions of which we are no longer a part, just as we do in other overseas markets. We accept that.

"However, we approach these talks constructively, respectfully, and in a spirit of sincere cooperation."