Euronext has begun a voluntary exchange offer for all shares in Hellenic Exchanges–Athens Stock Exchange (ATHEX), after receiving regulatory clearance in Greece. The offer, which runs from 6 October to 17 November 2025, proposes one new Euronext share for every 20 ATHEX shares, announced Euronext in a press release.

The move would add Greece to Euronext’s group of seven exchanges, extending its footprint into Southeast Europe. The company says the combination would allow Greek market participants to access its cross-border trading and post-trade infrastructure.

If the deal goes through, ATHEX trading is set to migrate to Euronext’s Optiq platform, and Greek securities could be included in the group’s Euronext Clearing and Euronext Securities operations. The group describes this as a step toward consolidating its post-trade setup across Europe.

For ATHEX, the integration would mean closer alignment with Euronext’s existing markets in Amsterdam, Brussels, Dublin, Lisbon, Milan, Oslo, and Paris. It would also make Athens the designated hub for Euronext’s activities in Southeast Europe.

Conditions and timeline

The offer requires that at least 67 percent of ATHEX’s voting rights be tendered, equivalent to about 38.8 million shares. If Euronext reaches 90 percent ownership, it plans to use a squeeze-out mechanism under Greek law to acquire the remainder. Settlement of the new Euronext shares and their listing on several Euronext venues are expected around 24 November 2025, provided all regulatory steps are completed.

Euronext estimates annual cost savings of about €12 million by 2028, mainly through system migration and central function harmonisation, with implementation costs of roughly €25 million. The transaction is expected to be financially positive once synergies are realised.

Board backs the offer

As part of the group’s federal governance model, the ATHEX CEO would join Euronext’s Managing Board, and a representative from Greece’s financial sector would take a seat on its Supervisory Board. The Hellenic Capital Market Commission would continue as ATHEX’s main regulator while joining Euronext’s College of Regulators. The ATHEX Board of Directors has expressed unanimous support for the transaction, and board members holding shares have committed to tender them. The outcome will determine whether Athens becomes Euronext’s eighth market and a new node in its post-trade network.