Brexit could cost the UK economy hundreds of billions in lost M&A activity over the rest of the decade, as firms hold off wheeling and dealing in the aftermath of the EU referendum.
Research for lawyers Baker and McKenzie said a long-drawn out negotiation and prolonged business uncertainty could result in activity shrinking by one-third by 2020, knocking $338bn (£258bn) off the value of deals completed in the UK.
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Even in the researchers' base case, total M&A will come in at just $749bn between 2016 and 2020, compared to the expected $988bn had the UK voted to stay in the EU.
Despite the downbeat forecasts, Baker and McKenzie M&A partner, Tim Gee said: "The M&A market in the UK won't come to a crashing halt even if it won't be at its previous pace. There are still plenty of buyers and sellers for the right deal at the right price."
Last week, Cambridge-based chipmaker ARM holdings was snapped up by Japan's SoftBank in a £24bn deal, as analysts said the falling value of the pound would make UK firms attractive propositions for foreign buyers.
"Regardless of the volume and value of UK specific deals the primacy of English law for many cross-border deals, even when they don't involve UK assets or business, will continue. London will also retain a remarkable concentration of financial, legal and economic talent," added Gee.
The other major deal in the pipeline is the tie-up of the London Stock Exchange with their German rival, Deutsche Boerse. The pair have insisted the deal is still on track despite the UK's vote to leave the EU.
Baker and McKenzie suggested European and global M&A could also take a hit from Brexit. In its worst case scenario, $1.6bn in total activity could be lost by 2020.