A merger would have created Europe's third biggest stock market

Deutsche Boerse approached its Swiss counterpart in July, hoping for "deeper co-operation," which raised hopes that the two could be about to be joined.

This would have created Europe's third-largest exchange bringing firms such as Nestle and Siemens into one market.

Deutsche Boerse also attempted to merge with the London Stock Exchange in 2000.

Despite deciding not to pursue merger talks with Frankfurt, SWX said it was still prepared to consider other forms of co-operation.

However, the Swiss bankers who control the SWX exchange were said to be reluctant to merge from the outset, with many regarding a tie-up as a threat to Swiss regulatory independence and banking secrecy.

Aside from creating Europe's third-largest market, a marriage of the two would have given Deutsche Boerse full control of Eurex - the world's biggest futures and options exchange.