Joanna Shields, vice president of EMEA at Facebook, has quit the social network to head up London’s Tech City.

Her departure comes as Facebook hunts for its first UK managing director leaving it with two senior vacancies at the top of the organisation in Europe.

Shields, who has been described as “the most influential person in European technology”, is to become the new chief executive of the Tech City Investment Organisation and will take up her role in January 2013.

Her hiring is real coup for David Cameron and the government’s efforts to bring new tech investment into London’s Shoreditch, dubbed Silicon Roundabout, and establish it as a centre for technical innovation and development.

Shoreditch has already seen the likes of Google, Intel and Cisco invest in the area and Amazon recently revealed plans to open a digital innovation hub in East London.

Shields said working in the UK for the past decade had proven to her that the UK had the potential to become a major force in digital innovation.

“Throughout my career I have had the privilege of working with great entrepreneurs and innovators to create thriving new businesses and industries. The seeds have been sown in East London for a dynamic and successful cluster: we have the infrastructure, the technology and the talent, now we need to accelerate the growth.

“I am looking forward to leading the Tech City Investment Organisation in the next phase of its development. With the right boost now, there is no reason why we can’t make London the number one location for tech in the world.”

“There are not many opportunities where you know from day one you can contribute on a huge level.

“I think London is an extraordinary city. This is the gateway to the world. It should not be a step-child to other cities. It should be in its rightful place as the centre for innovation in my world, the digital industries,” Shields said.

The Prime Minister  said the success of Tech City shows what can happen when the government “back some of our most innovative and aspiring companies to grow, helping the UK compete and thrive in the global race”.

Joanna’s experience will be hugely valuable in supporting Tech City as it goes from strength to strength, and as a Business Ambassador promoting the UK around the world,” Cameron said.

Shields, the former chief executive of Bebo, joined Facebook in April 2010 from AOL where she was president of people platforms.