Bruntwood has secured a 21,400 sq ft letting to payment protection firm KF Group at Atria in Bolton following a £5m refurbishment of the building.
KF Group is relocating 170 staff from Bury to Atria in Spa Road on the edge of Bolton town centre.
Bruntwood says the letting is the biggest in Bolton for more than five years. CBRE and Miller Metcalfe were joint letting agents on the deal.
The refurbishment works at Atria included the creation of a fully glazed central atrium and revamped office space. The 70,000 sq ft building is now at 96% occupancy.
Andrew Butterworth, sales director of Bruntwood, said: "Since acquiring Atria in 2007 we have invested substantially in the building to ensure it offers spacious and stylish office space of the high quality required by potential customers.
"It's a very popular building and it benefits from an excellent location and transport links, a flexible floor plan and the highest standard office space. This letting is testament to our flexible approach and our commitment to finding the perfect office solution for businesses."
Kirsty Littleford, senior surveyor at CBRE, said: "Despite the challenging office market across Greater Manchester, we have still seen consistent interest, particularly in smaller lettings of sub 5,000 sq ft. This is one of the most significant deals in Bolton in five years, which is testament to the quality of office space available in Atria. We expect the arrival of KF Group to open up employment opportunities in the area, and add valuable momentum to the town's economy."
Martin Terras, head of operations at KF Group, said: "Atria was the perfect choice for our office expansion. It's ideally located and is a real step-up in quality from our last premises, while its design really gives our new headquarters the gravitas that our introducers and customers would expect."