The media company will book a capital gain of €111 million, and plans to remain a tenant in the building with a long-term lease agreement.
"The transaction is one of the biggest ever among office buildings in the central business district," Harri-Pekka Kaukonen, president and CEO of Sanoma Corporation, said in the announcement. "There was very strong interest in the property, with offers from multiple countries."
Sanoma plans to use proceeds from the deal to pay off a part of existing debt.
Last December, Deka Immobilien purchased the Symphony Offices from Philips Pension Fund for approximately €215.1 million, making it the largest real estate transaction in the Netherlands in 2013 at the time.