The London office of Vinson & Elkins (V&E) has signed a lease to take a floor of the Walkie Talkie building at 20 Fenchurch Street, joining DWF as the building's second law firm tenant.

The Texas-headquartered firm will move from its current CityPoint home to the 24th floor of the Walkie Talkie next summer.

Based on marketing materials, there is space on the floor for at least 80 fee earners and 48 further secretarial and paralegal staff, giving V&E considerable room to expand against its current City headcount.

"There is space for a lot more than the 40-something lawyers currently in the office," said London office managing partner Alex Msimang. "The main driver for the move is to ensure we've got top quality space; it's not just about filling that space."

Msimang added that V&E has recently started the design and fit-out of the office, ahead of the 2015 relocation.

Earlier this month, DWF took up residence in the building, having secured a lease across two floors. DWF said the move into 20 Fenchurch Street amounted to "effectively doubling London headcount to 600 people over the next three years, to meet growing client demand".

The Walkie Talkie is now 90% let, with an estimated 1,700 staff now working in the building.

"We welcome Vinson and Elkins to the building and we're thrilled to have a global law firm of this caliber coming to 20 Fenchurch Street," said Kaela Fenn-Smith, head of commercial for Land Securities, which developed the property.

Canary Wharf Group and Land Securities were advised by Knight Frank and CBRE, while Vinson & Elkins was advised by Savills.