AshbyCapital and Helical have agreed a letting at One Bartholomew, in the City of London, to InfraRed Capital Partners.

The investment manager has signed a 15 year lease to take 19,609 sq ft of office space on the seventh floor.

One Bartholomew has been developed by Helical on behalf of owners, AshbyCapital, and comprises 221,000 sq ft of new Grade A office space across 12 floors.

It is located in Barts Square, a three-acre mixed-use development located between St Paul’s and Smithfield that comprises 236 apartments, 250,000 sq ft of office space over three buildings and 10 retail and restaurant units.

Gerald Kaye, chief executive at Helical, said: “One Bartholomew has already gained an outstanding reputation and this is borne out by the high calibre of tenants we are attracting. We are very pleased to welcome InfraRed to the building who are an expanding internationally recognised business.

“There are still high levels of demand for quality office space in London and Barts Square’s prime location in the heart of the City delivers this as well as extensive public realm improvements, excellent transport links and restaurant offerings.”

This latest letting at One Bartholomew follows the 15 year lease agreement with the University of Chicago Booth School of Business signed in April to take 43,000 sq ft of space, where it will create a new facility for its European campus. Trade Desk, the global technology company, has taken the top four floors, comprising 74,210 sq ft, meaning that only 77,000 sq ft over four contiguous floors remains available at the building.

Helical and AshbyCapital were advised by Savills, Ingleby Trice and CBRE. Knight Frank represented InfraRed.