St George's House on Peter Street in Manchester is now fully let after existing occupiers Travel Jigsaw and STA Travel took more space.
The 50,000 sq ft building is owned by GGM, the private property company of Ged Mason, chief executive of Salford recruitment firm, Morson Group.
GGM bought the building in 2009 and has conducted a full refurb, upgrading the offices and installing an air conditioning system.
Travel Jigsaw and STA Travel now occupy 29,000 sq ft and 7,000 sq ft respectively.
GGM's Peter Smith said: "Not many landlords are choosing to invest in their property portfolios at present, but we were keen to do so in order to meet the evolving requirements of our existing tenants.
"We are delighted that following this investment, two of our occupiers chose to remain at St George's House for their expansion."
Manchester surveyor OBI Property managed the refurb and is also the letting agent.
OBI's offices partner Will Lewis said: "It's great news that existing occupiers are not only growing their operations but are also making longer term lease commitments to the building which is located in a very exciting area of the city."