Brexit could cause big banks to lay off thousands: Analysts

Goldman expects sterling to weaken 11-percent if Brexit happens

Leading investment banks in the U.S. face certain fallout in the event that the U.K. leaves the European Union, with thousands of staffers set to see their jobs impacted.

That's the sentiment from a Keefe, Bruyette & Woods report, which says banks may have to increase expenses, shed staff and take a temporary earnings hit if U.K. voters approve the Brexit on June 23. Should the leave vote prevail, big banks would have to transition London staffers to cities in the EU to meet regulatory requirements, a large burden for the firms to shoulder.

"[A] U.K. vote to leave the EU would be a negative for the U.S. universal banks since costs could increase and capital markets activity could weaken," analysts wrote in a report Thursday. "Banks may have a two-year transition period and we'd expect the banks to experience both revenue and expense headwinds during the transition."