Cross-border stock exchange mergers look increasingly tough to execute, according to analysts at Jefferies.

The firm’s equity research unit reckons global M&A between bourses is not likely in the near term.

Regulatory frameworks and nationalistic views are two key reasons.

Both appear to be taking precedence over economic value or client benefit.

The comments come after Deutsche Boerse chairman Joachim Faber recently put the blame for the faltering tie-up with the London Stock Exchange on the Brexit vote.

The UK’s decision to leave the European Union has created strong headwinds for the €29 billion deal.

Neither the LSE or Deutsche Boerse have formally abandoned the tie up. The European Commission is set to deliver its formal verdict on 3 April.

“With the LSE/DB1 in the ninth inning of collapse, the general consensus amongst global exchange leaders was that large scale global M&A is increasingly difficult,” Dan Fannon, a New York-based equity analyst at Jefferies, wrote in a note on Monday.

“The regulatory framework as well as nationalistic views are primary factors that determine the merits of a transaction vs economic value or client benefit.”

While the global M&A match making game might be taking a pause in the short term, Fannon reckons that has the potential to change as regulatory regimes change and broader global uncertainty moderates (i.e. Brexit, European elections).

“In the meantime, without broad secular growth trends we believe that smaller M&A such as tuck-in acquisitions will continue to be the focus for most exchanges,” Fannon added.