World stock markets extended losses Monday as fears heightened that Britain could vote to leave the European Union in next week's referendum.

Tokyo's main stocks index dived 3.5 percent to a two-month low point by Monday's close, as worries over Britain's EU membership vote on June 23 sparked a rally in the safe-haven yen currency, which in turn hammered shares in Japanese exporters.

Craig Erlam, senior market analyst at Oanda trading group, said "risk aversion" continued to drive markets ahead of "a number of key risk events".

"The UK referendum next week is right at the top of this list given the destabilization effects that a vote to leave the EU could have on global markets," he said in a note to investors.

US stocks joined the global retreat, falling for a third straight day and pushing the S&P down 0.8 percent. But shares in professional networking company LinkedIn shot up 46.6 percent on news of its $26.2 billion takeover by Microsoft.

Shares of US travel-oriented equities were especially weak, with American Airlines, Delta Air Lines and United Continental all losing at least 3.5 percent in the aftermath of Sunday's deadly attack by a lone gunman at a gay nightclub in Orlando, Florida.

London's FTSE 100 index lost 1.2 percent. In the eurozone, Frankfurt's DAX 30 index and the CAC 40 in Paris were both about 1.8 percent lower. Banking stocks weighed in Milan, where the main index slid 2.9 percent to its lowest level since February.

In foreign exchange, the British pound hit two-month lows against both the euro and dollar.

The pound's latest tumble against the dollar "could be the tip of the iceberg" if Britons opt to quit the EU, said Alex Holmes, of Capital Economics.

The European single currency meanwhile sank as low as 119 yen, the lowest level since February 2013.

- Central banks on tap -

Markets also are on edge as the US, Japanese and British central banks meet this week.

Few expect any move on interest rates from the US Federal Reserve and Bank of England, but observers are divided over whether the Bank of Japan will announce more stimulus.

"Chances of the Fed raising interest rates this month are nil at this point, with a July raise looking less and less likely," Mark Vickery, of Zacks Investment Research, said in a note to clients.

For Oanda's Erlam, the Brexit risk is also playing a role in the Fed's timing.

"The Fed will meet this week and while the (May) jobs report may have given them a reason to put off raising interest rates again, the closing of the gap ahead of the UK referendum is likely the real reason behind the delay," he said.

Hong Kong's main stocks index tumbled 2.5 percent and Shanghai dived 3.2 percent, while Seoul sank 1.9 percent and Singapore 1.6 percent.

- Key figures at 2100 GMT -

New York - DOW: DOWN 0.7 percent at 17,732.48 (close)

New York - S&P 500 DOWN 0.8 percent at 2,079.06 (close)

New York - Nasdaq DOWN 0.9 percent at 4,848.44 (close)

London - FTSE 100: DOWN 1.2 percent at 6,044.97 (close)

Frankfurt - DAX 30: DOWN 1.8 percent at 9,657.44 (close)

Paris - CAC 40: DOWN 1.9 percent at 4,227.02 (close)

EURO STOXX 50: DOWN 2.0 percent at 2,853,52 (close)

Tokyo - Nikkei 225: DOWN 3.5 percent at 16,019.18 (close)

Hong Kong - Hang Seng: DOWN 2.5 percent at 20,512.99 (close)

Shanghai - Composite: DOWN 3.2 percent at 2,833.07 (close)

Euro/dollar: UP at $1.1292 from $1.1251 late Friday

Dollar/yen: DOWN at 106.19 yen from 106.93 yen

Pound/dollar: DOWN at $1.4245 from $1.4250

Source: AFP