The Bloomberg News Agency said the Blanchardstown Centre project is set to make about €1 billion.
The property includes about 176 stores and measures 1.2 million square feet. It is being sold by Dublin-based property investor Green Property Group.
International investors are vying to snap up Irish property assets, in a bid to tap into one of the fastest-growing economies in Europe.
Spokesmen for Blackstone and Green declined to comment on the sale.
The investment currently earns an annual rent of about €50m a year, according to a January statement by Green Property.
The new owner will be able to add as many as 600 homes to the project as well as stores, offices and leisure facilities at the 85-acre plot subject to planning approval, Green said in the statement.