London-headquartered Huddle, which has raised more than $15 million since its launch, will use the capital to expand its presence in the US, building a team in San Francisco led by co-founder Andy McLoughlin.

The funding round was led by Matrix Partners, a venture capital firm with offices in the US, China and India. Existing investor Eden Ventures and Charles McGregor, Huddle’s chairman, also participated.

Matrix general partner Josh Hannah has joined Huddle’s board of directors as part of the deal. He says, ‘It’s not often we come across an enterprise software company that is inherently viral and has the potential to redefine how we work with each other.’

Alistair Mitchell, co-founder and CEO of Huddle, comments, ‘If Facebook’s aspiration is to be the social fabric of the web, Huddle’s mission is to become its equal in the workplace, helping workers and businesses across the globe work better together.’

More than 50 per cent of Huddle’s users are based in the US.