Mirvac will buy the Harbourside shopping centre at Darling Harbour among a number of purchases along the eastern seaboard totalling $522 million.
The purchases will be completed with financial partners, particularly in Melbourne, where Mirvac has not previously had a large exposure.
Some redevelopment opportunities will arise, giving the group the chance to link tenants and operations with its existing buildings.
Mirvac has been very active in the commercial property market this year. It has bought a portfolio of office towers in Sydney, including 200 George Street, which is being redeveloped.
Under Thursday's deal, Mirvac will pay $250 million for Harbourside, $227 million for 367 Collins Street and $72 million for 477 Collins Street, Melbourne.
Chief executive Susan Lloyd-Hurwitz said the new assets would deliver attractive returns in excess of the group's stated targets and would be debt-funded.
"These acquisitions are in line with our strategy to hold income-producing CBD office assets that provide us with repositioning and development opportunities," she said.
The Harbourside centre would give Mirvac a greater share of the Sydney retail sector, with some "repositioning" opportunities.