Silicon Valley graduate Box has moved into its new London international headquarters from which it hopes to grow its European business.

The online file-sharing firm, which has more than 20m users worldwide, has chosen to make London its European base after opening an office in the capital last June.

Since then it has more than doubled its user growth outside the US and continues to expand in Europe, and plans to control those operations from its office off Regent Street.

David Quantrell, the company’s VP for EMEA, said: "As we expanded in Europe and witnessed growing demand for Box, we decided that London was not just an ideal location for an office, but also a great place to establish an official headquarters for our international operations.

"London is a central hub in the world economy and home to a fantastic pool of talent, and the UK government’s patent box regime and other recent economic initiatives provide us with a supportive environment for continuing to grow and expand aggressively aroundthe world."

Mayor of London Boris Johnson hailed the boost Box’s decision gives to London’s status as a hub of tech activity.

"This arrival is further welcome evidence of London’s status as a leading tech capital helped by the availability of a talented workforce, the work space and world-beating universities," he said.

The number of startups based around Silicon Roundabout, London’s tech scene in east London, has grown from 200 to more than 1,300 since the launch of the Tech City initiative in 2010.