The European Commission will veto a proposed combination between Deutsche Boerse and the London Stock Exchange shortly, three sources familiar with the matter said today.
The move will scupper plans to create Europe's biggest exchange.
The European Commission and Deutsche Boerse both declined comment.
The veto will be published within a matter of days, three people familiar with the deliberations told Reuters.
One of the people said that the ruling was expected for March 29.
A plan to combine the Frankfurt and London exchanges had only a slim chance of getting regulatory clearance after LSE last month declined to follow a demand from European Union competition regulators to sell an Italian trading platform.