Grade II* landmark offices in Broomhill, The Mount, have been sold to a private investor for an undisclosed seven-figure sum.
The building in Glossop Road was once headquarters for General Accident and Norwich Union before being let to current tenants the NHS and Voice Marketing.
The building came on to the market after the freeholder went into receivership.
Sheffield property agency Commercial Property Partners advised on the sale.
Rob Darrington, of CPP, said: “The Mount is an extremely attractive and elegant building, featuring a campus-style complex of two substantial buildings set within grounds.
“The building was originally a terrace of eight houses constructed in about 1830 by local architect William Flockton.
“The design followed a trend set in London’s Regent Park, with construction in the style of a country mansion, but in fact it contained several genteel dwellings.
“Flockton also used this as a basis when he built the nearby Wesleyan College (now King Edward VII School), also in Glossop Road in 1838. The Mount is mentioned in Nikolaus Pevsner’s seminal work The Buildings of England and is a very significant part of Sheffield’s architectural heritage. It will be cherished accordingly.”
Toby Vernon and Roger Haworth left CBRE, where they were both senior directors, to found Commercial Property Partners LLP in late 2013.
Rob Darrington and Ed Norris joined as partners shortly afterwards, from Lambert Smith Hampton.
Rob said: “Our regional focus is on Yorkshire, the North Midlands and the North East. Our large patch is an advantage.”