Nyse Euronext said in December that it would buy Atos Origin's stake in the AEMS JV in a move that would split the venture into two separate entities.

Under the agreement Nyse Euronext is acquiring the 50% stake in AEMS held by Atos Origin and repurchasing ownership of the NSC cash trading and Liffe Connect derivatives trading platforms, as well as AEMS's third-party exchange technology business. At the same time Atos Origin is acquiring the third-party clearing and settlement and capital markets businesses from AEMS.

But according to Agence France-Presse, around 100 AEMS staff staged the strike action in protest over the package offered to the 878 employees affected by the separation.

Michel Rouge, an offcial from the French union Confédération Française Démocratique du Travail (CFTD) told reporters that the union was not opposed to the split but wants improved conditions for affected staff.

The union is seeking a guarantee of 36 months employment for staff remaining with Euronext - thought to be two-fifths of the total affected - and those that will stay with Atos Origin, as well as a one-off payment of EUR36,000 for each employee.

The 50/50 JV was formed between Euronext and Atos Origin in 2000 to manage internal software development and licensing the exchange's technology platforms NSC and Clearing 21 to third parties. The JV was later merged with the Euronext.Liffe Market Solutions business.

In separate news, The Athens Stock Exchange is closed today after strike action by workers at Greece's central bank prevented the clearing and settlement of transactions.

The central bank employees, who are protesting against pension reforms, began the strike yesterday.

According to press reports the strike has prevented the clearing and settlement of trades from Monday's session and is also thought to be the root cause of a trading halt between 10.52 am and 2.45 pm yesterday.

In a statement, Hellenic Exchanges says it has cancelled today's trading Session due to the "inability of Bank of Greece to perform cash settlement of transactions".

"Until such time as the Bank of Greece is able to perform the cash settlement of transactions, the ATHEX Chairman, after taking into consideration the serious dangers to the smooth functioning of the market, decided that today's trading session be cancelled, in order to protect investors and ensure the smooth functioning of the market," says the statement.