The Lloyd's building is to be sold to private Irish-based property company Shelbourne Development for an estimated £240m, revealed a report.
The sale is expected to be completed by the beginning of March, said the report.
Shelbourne, run by Garrett Kelleher, has agreed terms for the Richard Rogers Partnership-designed building with current owners Deka.
Deka, Germany's largest operator of open-ended commercial property funds, is expected to make profits of at least £60m from the sale.
It bought the building for £180m in 1996, meaning the £240m price tag represents a 36% rise in value, said the report.
