A British vote to leave the European Union sent sterling plunging on Friday and hammered equities across the world as turmoil swept through global markets.Such a body blow to global confidence could well prevent theFederal Reserve from raising interest rates as planned thisyear, and might even provoke a new round of emergency policyeasing from all the major central banks.Risk assets were scorched as investors fled to thetraditional safe-harbours of top-rated government debt, Japaneseyen and gold.Billions were wiped from share values as FTSE futures fell 7percent, EMINI S&P 500 futures 5 percent andJapan's Nikkei 7.6 percent. European stock markets wereset to open more than 10 percent lower.The British pound collapsed no less than 18 U.S. cents,easily the biggest fall in living memory, to hit its lowestsince 1985. The euro in turn slid 3.2 percent to $1.1012as investors feared for its very future.Nearly complete results showed a 51.8/48.2 percent split forleaving, setting the UK on an uncertain path and dealing thelargest setback to European efforts to forge greater unity sinceWorld War Two.Sterling sank a staggering 10.1 percent at one point and wasslumped at $1.3582, having carved out a range of $1.3228to $1.5022. The fall was even larger than during the globalfinancial crisis and the currency was moving two or three centsin the blink of an eye."It's an extraordinary move for financial markets and alsofor democracy," said co-head of portfolio investments ofLondon-based currency specialist Millennium Global RichardBenson."The market is pricing interest rate cuts from the bigcentral banks and we assume there will be a global liquidity addfrom them in the next few hours," he added.The shockwaves affected all asset classes and regions.The safe-haven yen sprang higher to stand at 102.15 perdollar, having been as low as 106.81 at one stage. Thedollar decline of 4 percent was the largest since 1998.That prompted warnings from Japanese officials thatexcessive forex moves were undesirable. Indeed, traders werewary in case global central banks chose to step in to calm thevolatility.One source told Reuters the Bank of England was in touchwith other major central banks ahead of the market open thereand the Bank of Japan Governor Haruhiko Kuroda it was ready toprovide liquidity if needed to ensure market stability.Other currencies across Asia and in eastern Europe as itwoke up suffered badly on worries that alarmed investors couldpull funds out of emerging markets. Poland, where many of theeastern Europeans in Britian come from, saw its zlotyslump 7 percent.RECESSION FEARSEurope's natural safety play, the 10-year German governmentbond, surged to send its yields tumbling back into negativeterritory and a new record low.MSCI's broadest index of Asia-Pacific shares outside Japanslid almost 5 percent, while Shanghai stockslost 1.1 percent.Financial markets have been gripped for months by worriesabout what Brexit, or a British exit from the European Union,would mean for Europe's stability."Obviously, there will be a large spill-over effects acrossall global economies if the "Leave" vote wins. Not only will theUK go into recession, Europe will follow suit," was the gloomyprediction of Matt Sherwood, head of investment strategy at fundmanager Perpetual in Sydney.Investors duly stampeded to sovereign bonds, with U.S.10-year Treasury futures jumping over 2 points in anextremely rare move for Asian hours.Yields on the cash note fell 24 basis points to1.49 percent, the steepest one-day drop since 2009 and thelowest yield since 2012.The rally did not extend to UK bonds, however, as ratingsagency Standard and Poor's has warned it would likely downgradethe country's triple A rating if it left the EU.Yields on 10-year gilts were indicated up 20 basis points ataround 1.57 percent, meaning higher borrowingcosts for a UK government already struggling with a large budgetdeficit. Standard and Poor's has said it will strip the UK ofits triple A credit rating.Across the Atlantic, investors were pricing in even lesschance of another hike in U.S. interest rates given the FederalReserve had cited a British exit from the EU as one reason to becautious on tightening."It adds weight to the camp that the Fed would be on hold. AJuly (hike) is definitely off the table," Mike Baele, managingdirector with the private client reserve group at U.S. Bank inPortland, Oregon.Fed funds futures <0#FF:> were even toying with the chancethat the next move could be a cut in U.S. rates.Commodities likewise swung lower as a Brexit would be seenas a major threat to global growth. U.S. crude shed $3.00to $47.11 a barrel in erratic trade while Brent fell asmuch as 6 percent to $47.83 before clawing back to $48.18.Industrial metal copper sank 3 percent but goldgalloped more than 6 percent higher thanks to itsperceived safe haven status.