* FTSEurofirst 300 falls 3.7 pct to six-year closing low
* Banks tumble on nationalisation concerns
* UBS down 14 percent, Anglo American falls 17 pct
LONDON, Feb 20 (Reuters) - European shares hit a six-year closing low on Friday, with investors dumping equities to grab assets such as bonds and gold as the deepening economic downturn hit market sentiment and raised fears of bank nationalisations.
Safe-haven buying lifted U.S. gold futures to a seven-month high above a key psychological level of $1,000 an ounce, while euro zone government bonds rose after record low readings of euro zone purchasing managers' indexes.
The FTSEurofirst 300 <
> index of top European shares closed 3.7 percent down at 735.74 points after hitting a low of 736.27 points -- its lowest since early 2003.Banking stocks suffered the most, with Deutsche Bank <DBKGn.DE> falling 9.6 percent, Credit Agricole <CAGR.PA> slipping 9 percent, Royal Bank of Scotland <RBS.L> down 11.5 percent, Dexia <DEXI.BR> dropping 8.4 percent and Commerzbank <CBKG.DE> falling 8.6 percent.
"When you look at historically poor data, see companies reporting results considerably below market expectations and when management teams offer a negative outlook for the rest of the year, there is no surprise that market confidence continues to take a battering," said Henk Potts, strategist at Barclays Stockbrokers.
"Certainly in the first quarter, we anticipate the market to continue to be very volatile. We are suggesting that the best strategy is to remain defensive and pick the stocks that have reliable earnings stream."
Swiss bank UBS <UBSN.VX> hit record lows before closing 14 percent lower on concerns a widening U.S. tax probe will weaken Switzerland's strict privacy rules and damage the country's wealth management industry.
Banking shares were hit in other markets too. In the U.S., Bank of America Corp <BAC.N> plunged 18 percent, while Citigroup <C.N> shares plummeted 21 percent.
The FTSEurofirst 300 fell 7.6 percent this week. It is down more than 11 percent so far this year after tumbling 45 percent in 2008 on a credit crisis -- the worst since the Great Depression of the 1930s.
A large number of developed economies, where soaring house prices fuelled a long-running credit boom, are bearing the brunt of recessions induced by the abrupt halt to lending as the scale of bank exposure to high-risk debt began to bite.
"The ongoing flood of bad news has increased the risk aversion of investors," said Markus Reinwand, equity strategist at German bank Helaba. "A trigger for a rapid shift in sentiment is not in sight."
INVESTORS REMAIN WARY
Germany's upper house approved a 50 billion euro ($62.88 billion) stimulus package to help it withstand its worst recession since World War Two, but investors remained wary.
"In a bear market it's perhaps always easy to postulate about moving in and cherry-picking keenly priced stocks, but so long as the overall sentiment remains so entrenched and so negative, this could well prove to be a hard sell too," said Paul Webb, head of trading at CMC Markets.
Energy stocks slipped, also under pressure due to a 2.9 percent drop in crude. BP <BP.L>, Royal Dutch Shell <RDSb.L>, BG Group <BG.L>, Tullow Oil <TLW.L>, Repsol <REP.MC>, Total <TOTF.PA> and StatoilHydro <STL.OL> were down 2.5 percent to 6.9 percent.
Building material giants Saint-Gobain <SGOB.PA> and Lafarge <LAFP.PA> fell 15 percent and 2.4 percent respectively after each announced 1.5 billion euro rights issues as they turned to investors to buttress them against the impact of the crisis.
Anglo American <AAL.L> fell 17 percent after the miner scrapped its 2008 final dividend to conserve cash and said it will cut 19,000 jobs.
AXA <AXAF.PA> plunged for a second consecutive day, down 18.4 percent, as brokers downgraded the stock after the French insurer posted a second half loss on Thursday.
Swiss Life <SLHN.VX> jumped 8.5 percent after the insurer said its capital base improved at the end of 2008, easing investor fears it might need to raise more capital.
Across Europe, the FTSE 100 index <
>, Germany's DAX < > and France's CAC 40 < > were 3.2 percent to 4.3 percent down. (Additional reporting by Blaise Robinson in Paris, Joanne Frearson in London and Peter Starck in Frankfort; Editing by Sharon Lindores)