US firm McDermott Will & Emery is planning to relocate its UK headquarters from its current London home in the City to the heart of Mayfair.

The firm’s new headquarters will occupy the whole of The Lazari Building, which was formerly home to the Fenwick department store. McDermott is expected to take residency in 2028 on a 15-year lease following completion of construction works.

The relocation plans come just a month after McDermott said it was in advanced merger talks with New York firm Schulte Roth & Zabel.

The news of the move comes just two years after McDermott relocated to its current home at 22 Bishopsgate. The move to The Lazari Building at 7 Brook Street will give the firm significantly more office space – 115,000 sq ft, compared to about 27,300 sq ft at its current office, according to Estates Gazette.

The firm currently occupies just one floor at 22 Bishopsgate in a building shared with other tenants, including US rivals Skadden, Perkins Coie, Covington & Burling and Cooley. It will occupy eight floors of office space for itself at The Lazari Building.

Aymen Mahmoud, McDermott’s London managing partner, said: “This move is a significant milestone for McDermott. For us, it’s a space that represents our ambition to be at the pinnacle of the London legal market. Mayfair is exactly where we belong: at the centre of the conversation and shoulder to shoulder with our clients.”

The new office space will have a “spacious timber-lined reception” that connects to a “sculpted light-filled and landscaped atrium running up the building”. The building will also sport a roof-top garden entertainment space, a mezzanine bar, a wellness centre, changing rooms and cycle parking. The building will also house retail space that faces on to New Bond Street.

Len Lazari, director at property investment and development company Lazari, said: “This was a unique opportunity to establish a new development on an historic site, on London’s most exclusive retail street. There was a responsibility to deliver a scheme which provides revitalised, contemporary office and retail amenities, while at the same time being sympathetic and in keeping with its historic surroundings.”

McDermott was advised by Slaughter and May on the transaction, while Lazari was represented by real estate specialist Forsters.

Prior to moving to 22 Bishopsgate, McDermott spent more than a decade at Salesforce Tower, located at 110 Bishopsgate.