LONDON, July 15 (Reuters) - Investment bank revenues arelikely to fall about 11 percent this year, due in part touncertainty and lower client activity following Britain'ssurprise decision last month to leave the European Union,according to Boston Consulting Group (BCG).
BCG said in a report released on Friday that revenues werelikely to fall to $204 billion this year, down from $228 billionin 2015 and compared with an earlier forecast of $212 billion.
Revenues related to European mergers and acquisitions coulddrop as much as 60 percent, while those related to Europeanequity capital markets may fall as much as 50 percent, it said.
The disruption from Brexit "will likely affect both theshort-term revenue outlook, through market shocks and loss ofbusiness confidence, and the long-term revenue outlook throughdisruptive business transformation," the consultancy said.
Britain has to negotiate new trading terms with the EuropeanUnion after it voted in a referendum last month to leave thebloc. Banks such as HSBC have said they would shiftstaff to the EU unless broad "passporting" rights were kept.
Banks registered in the Britain are currently granted a"passport" to offer their services across the EU from their UKbases, saving money on capital requirements and other costs bynot having to set up in each member state.
Setting up separately capitalised subsidiaries could costbanks up to an extra 40 billion euros ($44.5 billion), BCG said.
"Banks that are active in asset classes requiring a localpresence within the EU may no longer see a reason to maintain aLondon operation, and will thus shift operations to a new hub,"the report said.
"Other banks already short on scale may lack the appetite tomake additional investments and choose to exit certain businesslines."
($1 = 0.8986 euros) (Reporting by Andrew MacAskill; Editing by Mark Potter)