* Index down 1.8 percent, lowest close since March 17
* Focus on banks, high oil price, rising inflation
* Earnings estimates seen falling as economic growth slows
By Peter Starck
FRANKFURT, June 20 (Reuters) - European shares fell for the third straight day on Friday, led by a slide of more than 5 percent in Dutch-Belgian financial group Fortis <FOR.AS>, with the focus on the health of banks, high oil prices and rising inflation.
The FTSEurofirst 300 index <
> of top European shares dropped 1.8 percent to 1,222.51 points, its lowest close since March 17 and down 3.5 percent for the week.The benchmark index climbed 15 percent between mid-March and mid-May as investors cheered the U.S. Federal Reserve-sponsored bail-out of U.S. investment bank Bear Stearns. Those gains have now been wiped out.
Erste Bank attributed the downturn to high oil prices, persistent uncertainty stemming from the financial crisis, the strong euro and high inflation.
"Unless these essential parameters change, we expect a continued weak stock market performance," Erste said in a note.
A month ago some bankers and analysts said the worst of the financial crisis appeared to be over, but recent banking sector developments have once more discouraged investors.
Friday's top victim was Fortis, down 5.1 percent, on worries the group may need to raise more capital.
"The market is most worried about the solvency situation of Fortis," Rabo Securities said in a note.
"We estimate that Fortis only has 2-4 percent cushion in its insurance equity portfolio before it has to stop realising equity capital gains. If stock markets decline further there is the risk for negative equity impairments via the income statement," Rabo Securities said.
British mortgage lender HBOS <HBOS.L> fell 4.9 percent and Swiss UBS <UBSN.VX> lost 3.3 percent.
"UBS likely to have the greatest negative P&L (profit and loss account) impact in the second quarter of 2008, reporting another loss at group level," Lehman Brothers said in a note assessing the need for further asset writedowns at European investment banks.
The DJ Stoxx European bank index <.SX7P> fell 1.8 percent. It has underperformed the broader market, declining almost 22 percent from its May peak.
"Worries about further write-offs as well as liquidity problems in the financials sector contributed to this trend," Raiffeisen Bank said, adding that high raw material prices would keep alive corporate earnings revision fears in other sectors.
EARNINGS DOWNGRADES
Citigroup said current consensus earnings estimates for European companies suggested 3 percent growth in 2008. The consensus has come down from 11 percent growth at the end of January.
"These estimates still appear too optimistic. We see more downgrades ahead," Citigroup said.
Shares in Italian carmaker Fiat <FIA.MI> fell more than 9 percent to their lowest in nearly two years after Chief Executive Sergio Marchionne said sales were a "disaster".
German fashion house Escada <ESCG.DE> warned that sales and profits for the fiscal year to end-October would not meet its targets, sending its shares down 6.8 percent in floor trading <ESCG.F> after the electronic market's close.
BHP Billiton <BLT.L>, down 3.2 percent, led losses in the heavyweight mining sector <.SXPP> as the price of gold <XAU=> retreated from Thursday's one-week highs around $908 an ounce.
Anglo American <AAL.L> fell 2.4 percent and Rio Tinto <RIO.L> lost 1.7 percent.
"I'd be happy to see a rebound in equities, but this is not going to be easy," said Thierry Lacraz, strategist at Swiss bank Pictet in Geneva.
"There is only one problem -- the banks, the banks, the banks -- after the Citigroup warning yesterday and the Moody's rating cuts for (U.S. bond insurers) Ambac and MBIA," he added.
On Thursday, the finance head of Citigroup <C.N>, the largest U.S. bank, said the group could have substantial subprime writedowns in the second quarter.
Among key issues for investors has been the spiralling cost of fuel and food that has prompted central bankers to reiterate their intention to tackle inflation even at the expense of economic growth.
"Clearly the threat of inflation has been growing in central bankers' and in investors' minds over the last few trading sessions and again, that said, it's easy to understand why some short-term optimism has dissipated," said Henk Potts, investment strategist at Barclays Stockbrokers.
Citigroup said in a European equity strategy note: "The latest weakness in global equities looks different to that seen earlier in the year. The focus seems to have shifted from weak growth to rising inflation and the potential monetary response."
Higher borrowing costs would squeeze company profit margins, which are already under pressure from rising prices for raw materials and energy as well as wage claims.
"We expect that in connection with a gloomy macroeconomic outlook for the eurozone for 2008 as well as for 2009, sustainable index gains are quite unlikely during the next months," Raiffeisen said. (Additional reporting by Sitaraman Shankar and Amanda Cooper in London; Editing by Quentin Bryar)