GPT has locked in QBE for its state-of-the-art building, which is expected to open in late 2020.
The insurer will move out of the Eclipse Tower, in Station Street, and into the nearby 32 Smith Street development, where it will occupy 51 per cent of the 26,400sqm office building for at least 10 years.
GPT head of office and logistics Matthew Faddy said the new building would be a feature in Parramatta's CBD transformation.
QBE Australia and New Zealand chief operating officer Renée Roberts said the move would be a "significant one" for the insurer.
"It will bring together our existing Parramatta-based teams with those currently located at Sydney Olympic Park, into one purpose-built, modern and flexible workspace," Ms Roberts said.
Construction is yet to begin on the Smith Street building, which is GPT's first move in the Burgeoning Parramatta office market.