Ropes & Gray is set to double its headcount in London, after the Boston-headquartered firm signed a twenty year lease for a larger 45,000 sq ft office at 1 New Ludgate.

The new premises, a contract for which was signed by Ropes and Land Securities this week, will accommodate twice the number of lawyers and staff housed by Ropes' current City office.

Ropes, which has 80 lawyers and 40 support staff at the 5 New Street Square base it sub-lets from Taylor Wessing, is expected to move over to Ludgate in September 2015.

Mizuho Group, one of Japan's largest financial services companies, has already pre-let the adjoining office space at 2 New Ludgate.

"We opened the London office four years ago with only four lawyers and have since grown to over 80 lawyers and more than 40 staff – a significant growth spurt," said London managing partner Mike Goetz (pictured).

"This move reinforces our commitment to the London market and will also allow us to further develop our core practice groups over our next phase of growth."

Goetz said the new office would also give the firm a "fantastic vantage point" for its client base between Mayfair-based funds and larger financial institutions in the City.

The London managing partner launched the London office in 2010 with fellow Freshfields Bruckhaus Deringer partner Maurice Allen and senior US-based partners Newcomb Stillwell and David Chapin.

At the time, Allen said he and Goetz needed "an environment where we can build a successful practice…They [Ropes] are very supportive and the firm's management are realistic about what we want to achieve."

Earlier this week, the firm announced it will add to its partner headcount from August, after securing the hire of Pinsent Masons funds partner Monica Gogna.

Gogna, who trained at Mayer Brown and spent seven years in the financial services team of Clifford Chance, advises banks, investment managers private banks, foreign governments and regulators on a wide range of regulatory issues.