Image copyright Getty Images Image caption Facebook's Nicola Mendelsohn announced the expansion at the CBI conference

Facebook will expand its presence in the UK by 50% when it opens its new London headquarters in 2017, the US technology giant has announced.

It will hire 500 additional employees, including engineers, marketers, project managers and sales staff.

"The UK remains one of the best places to be a tech company," said its London-based executive, Nicola Mendelsohn.

Facebook's new headquarters will be in Fitzrovia at a site that is currently undergoing redevelopment.

The majority of the new staff will be based there.

Ms Mendelsohn announced the expansion at the Confederation of British Industry conference.

'High-skilled jobs'

"Many of those new roles will be high-skilled engineering jobs as the UK is home to our largest engineering base outside of the US," said Ms Mendelsohn, who is vice-president for Europe, the Middle East and Africa at Facebook.

The company said some of its most important innovations had been developed in the UK, including Aquila, a solar-powered, unmanned plane that provides internet connectivity to remote regions.

That project is located at Facebook's only UK site outside London, in Somerset.

Engineers at Facebook's London office are continuing the development of Workplace, a platform devised to improve communications between workers within a business, launched last month.

Image copyright Facebook Image caption It is not clear whether the new HQ will follow the tech trend for unusual office facilities

There has been speculation following the UK referendum vote to leave the EU that international companies may reconsider investing in the UK.

However, Facebook's announcement comes just a week after Google announced a £1bn investment in a new London headquarters and the creation of 3,000 new jobs by 2020.

London's mayor, Sadiq Khan welcomed the Facebook news.

"Facebook's decision to expand in London is further evidence that London's strength as a tech hub keeps on growing," he said.

"The capital's vibrant tech scene is the envy of Europe and Facebook's continuing commitment is another sign that London is open to talent, innovation and entrepreneurship from all four corners of the world."