By Jeremy Gaunt, European Investment Correspondent

LONDON (Reuters) - The coming week should signal whether a year of voracious risk appetite on financial markets is going to end with a bang, a whimper or, quite possibly, a thundering great clunk.

Not only will investors have to deal with confidence-sapping fallout from Dubai's debt problems, they will also be faced with a European Central Bank that may well flag an end to its crisis-driven program of providing cheap money to banks.

Investors have long said that when central banks launch such exit strategies -- stopping the flood of money they pumped into the financial system to stop a wholesale global collapse -- assets are likely to become highly volatile.

"The ECB will have more fundamental and longer-term impact than Dubai," Emiel van den Heiligenberg, head of asset allocation at Fortis Investments in London.

There is no doubt, however, that when Dubai told creditors of its Dubai World and property group Nakheel that debt repayments will be delayed, it handed global investors a major shock.

The financial world is so intertwined that assets as diverse as European car makers and the Mexican peso have been hit by Dubai debt fears -- the former because they are part-owned by Gulf sovereign wealth funds, the latter because of the implication for banks, lending and economic recovery.

Emerging market stocks <.MSCIEF> have fallen sharply since Dubai's announcement while the dollar has rebounded, both signs of clear risk aversion from market players.

How much further this goes may depend on whether other Gulf emirates, such as cash-rich Abu Dhabi, come to the aid of over-leveraged Dubai, as many expect.

Investors will also be looking to see just who is exposed, particularly among banks. And they may wonder whether there was an over-reaction with memories still fresh about last year's Lehman Brothers collapse.

But it may also be that they have taken -- and will continue to take -- the Dubai debt crisis as an excuse to sell riskier assets that have performed stunningly well this year to book profits by year end.

"The general comment (among investment managers) is 'this is a good opportunity to lock in gains'," said Peter Lucas, investment strategist at RBC Wealth Management.

DRYING UP

The Dubai "black swan" came waddling out of the desert just as investors were preparing to face a world where the liquidity that has driven risk appetite this year may be about to become less plentiful.

When the ECB meets on Thursday, it is expected to leave rates on hold at a record low of 1 percent. But it is also seen announcing how it plans to start pulling back supplies of cheap and generous liquidity.