* Sector capital adequacy reached 15.5 pct at end-September
* Adverse scenario shows need for CZK10.5 bln capital hike
* Sees corporate bad loans at 11.4 pct by end-2011
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PRAGUE, Nov 29 (Reuters) - Czech banks remain stable enough to withstand potential adverse shocks, though it would cost the sector three times as much to recapitalise than previously thought in a worst-case scenario, the central bank said on Monday,
In a regular financial health update, the central bank said the capital base of the whole sector would remain above the regulatory minimum of 8 percent of assets even in the event of adverse developments in the domestic and external economies plus renewed uncertainty on financial markets.
"Despite the relatively high credit and market losses and weakened operating profit in both macroeconomic scenarios, the banking sector as a whole remains stable and its aggregate capital adequacy stays constantly above the regulatory minimum of 8 percent," the bank said.
"This is achieved despite the conservative settings of many of the assumptions of the individual scenarios which suggest rather a more pessimistic development."
The sector capital adequacy rate, the key reason for its stability, reached 15.5 percent at the end of September from above 14 percent in March, the bank said.
Under the pessimistic scenario, which the central bank said was based on highly implausible developments in domestic economic activity, some banks would have to increase their regulatory capital by nearly 10.5 billion crowns ($562 million) or 0.3 percent of GDP.
That figure was above an estimate made by the bank in August when it saw the need for a capital hike in the worst-case scenario at 3.5 billion crowns.
But the amount represents only a fragment of the banking sector's profitability and would pose no systemic threat.
The adverse scenario assumes a decline in external demand due to renewed uncertainty about financing euro zone countries' debt.
Non-performing corporate loans will rise to close 11.4 percent at the end of 2011 from around 9 percent in September this year under the baseline scenario, which assumes the bank's official forecast for 2.3 percent economic growth this year, the bank said.
Non-performing household loans should rise marginally next year and then gradually decline to about 5.5 percent at the end of 2012.
The debt crisis in the euro zone was ratcheted up another notch at the weekend with an 85 million euro bailout deal for Ireland. Analysts said the agreement has cast doubts on the relevance of the stress tests carried last summer on lenders in the single currency area, which no Irish banks failed.
However, Czech banks have come through the global financial crisis without requiring any state aid thanks to a strong deposit base relative to their loan exposure and little dependency on external financing.
The sector is dominated by traditional Czech banks with strong savings balances that have been acquired by west European lenders in the past decade.
The biggest players are the local units of Erste Bank <ERST.VI>, KBC <KBC.BR> and Societe Generale <SOCGN.PA>. (Reporting by Jana Mlcochova; editing by Patrick Graham, John Stonestreet)