* 15-40 bln Swiss franc client assets at risk from tax deals
* Confirms medium-term goals at investor day
* Targets 15 bln franc pretax profit in 3-5 years from 2009
* CEO says could take time for consistent inflows
* Shares down 1.1 percent; outperform European peers
(Adds more analyst comment, details from presentation)
By Jason Rhodes and Steve Slater
ZURICH/LONDON, Nov 16 (Reuters) - UBS faces a moderate loss of about 10 percent of European client assets due to deals Switzerland is striking with other countries to clear up the problem of untaxed secret bank accounts.
Switzerland's largest bank, which confirmed ambitious medium-term goals on Tuesday, said up to 40 billion Swiss francs ($41.64 billion) were at risk from changes in tax regulations.
Following Swiss government agreements with Britain and Germany to clean up untaxed accounts and with other large neighbours expected to follow suit, UBS faces demands for clients' unpaid tax and the possibility of more clients withdrawing money from offshore accounts.
UBS said clients from Austria, Britain, France, Germany and Italy had already withdrawn 20 billion Swiss francs ($21 billion) from offshore accounts in the past 12 months, according to slides for a presentation at an investor day in London.
"We believe that 15-40 billion (francs) are still at risk as a result of changes in tax regulations," said Juerg Zeltner, head of UBS wealth management, adding UBS had 320 billion of invested client assets in Europe at end-September.
Angered that secret Swiss accounts were used to dodge taxes, Switzerland's neighbours have sought to break through its bank secrecy by buying stolen client data, souring relations.
"The 40 billion francs at risk figure is just 5 percent of total assets under management and the sort of amount they were losing per quarter in 2008 and they could easily survive such a loss," said Helvea analyst Peter Thorne.
UBS remained on track to reach an annual pretax profit of 15 billion francs by 2014 at the latest, the bank said, despite a shock third-quarter investment banking loss due to low client activity after UBS cut risky, but potentially, lucrative proprietary trading.
Investment bank head Carsten Kengeter told the investor day UBS was well placed to benefit from an upturn in client activity, though trading growth would also mean more risk.
Shares in UBS were down 1.1 percent at 1341 GMT, outperforming a 1.5 percent fall in the Stoxx European 600 bank's index.
TAX PRESSURE
Switzerland agreed last month with Germany and Britain to resolve the issue of untaxed accounts and to introduce a withholding tax on future deposits. It is expected to seal similar deals with other European nations.
The tax rate and retroactive penalty on offshore accounts still have to be decided but the banks are likely to have to transfer billions of clients' money to foreign tax authorities, while trying to persuade them to keep their accounts.
"We can cope with the European situation because we are very well positioned in Asia-Pacific, emerging markets and the ultra high net worth segment, which are growth areas," said spokesman Christoph Meier at UBS, the top private bank in these markets.
UBS said last month that inflows from Asian and super-rich clients helped it stop bleeding client money for the first time since early 2008, a key turnaround goal.
Chief Executive Oswald Gruebel told the investor day he expected net new money to continue improving, although the bank had some way to go before it sees consistent inflows.
Julius Baer, Switzerland's biggest listed pure play wealth manager, said last week that growth in emerging markets would more than compensate for any hits to its client assets resulting from new European tax deals.
The larger Swiss banks have invested heavily to capture booming wealth in Asia and other growth markets as well as building up onshore as a clampdown on tax havens has put the brakes on their traditional European offshore markets.
UBS has launched a high-profile advertising campaign and is sprucing up its Swiss branches to try and restore its image and lure back clients who pulled nearly 400 billion francs from the bank after it wrote down more than $50 billion in the credit crisis and was the target of a damaging U.S. tax probe.
The Swiss government said on Tuesday U.S. tax authorities had withdrawn a summons against UBS after the bank was forced to hand over details of 4,000 accounts of clients suspected of tax evasion, ending that dispute.
After a sharp fall during the crisis, shares in UBS have gained around 5 percent so far this year, versus a 19 percent fall in Credit Suisse and a 6 percent dip in the sector index.
However, shareholders will have to wait for UBS to start returning profits. Chief Financial Officer John Cryan reiterated on Tuesday the bank does not expect to pay dividends for some time to come as it uses retained earnings to meet stricter capital regulations. (Additional reporting by Emma Thomasson, Editing by David Cowell and Erica Billingham)