JUSTIN TALLIS | AFP | Getty Images

Britain's vote to leave the European Union (EU) could significantly reduce the relevance of the European Investment Bank (EIB), an analyst told CNBC.





The EIB, a lender owned by EU member states, is particularly vulnerable to Brexit as the U.K. is one of its key investors and any such divorce from the EU would likely cause a major headache for governments across the continent. "(Brexit) reduces the EIB's firepower, the bank is in danger of becoming a less relevant institution and its credibility is in question," Chris Beauchamp, chief market analyst with IG, said on Friday. "Of course, the result of Italy's referendum could make things a whole lot worse too…" he added. Italy's referendum on December 4 has put Euro zone fears back on the table as the country is expected to reject the proposed constitutional reforms.

Only EU member states allowed

The EIB's total capital amounts to around 243 billion euros ($257 billion dollars) according to Reuters, though just 21 billion euros of this is paid in. Britain's share of the amount paid-in is approximately 3.4 billion euros or close to 16 percent. Only EU member states are able to pay in to the EIB which would rule out the U.K. once Brexit has been completed. However, it is technically possible for a transitional deal, or even a change to the ruling altogether to be successfully negotiated in that time.

Plugging the gap