* Euro down 0.3 pct at $1.3443 EUR=
* Moody's cuts Allied Irish Bank rating
* CFTC data shows shift to euro longs
* Dollar holds above 84 yen JPY=
(Adds quotes, updates prices)
By Tamawa Desai
LONDON, Sept 27 (Reuters) - The euro fell against the dollar on Monday, extending earlier losses, as ratings firm Moody's cut Anglo Irish Bank's debt and kept it on review for downgrade, highlighting concerns over the euro zone banking sector.
The euro hit a session low of $1.3426 EUR=, down 0.3 percent on the day by 0923 GMT, coming off a five-month high of $1.3496 EUR= hit on Friday.
"The Moody's downgrade was moderately significant as it takes them ahead of others ... to one notch above junk, and it still remains under review," said Adam Cole, global head of FX strategy at RBC Capital Markets. [ID:nWLA3886]
"With the prospect of more easing by the U.S. Federal Reserve priced in, the focus may move back to Europe."
The single currency had edged lower versus the dollar on profit-taking after gaining some 4 cents since last week, and after failing to break a barrier at $1.3500, traders said.
The euro's next key level stood at $1.3510, a 50 percent retracement of its fall from above $1.51 last November to its June low below $1.19. There was also talk of a barrier at $1.3525 with stop-loss buy orders above that level.
European Central Bank tenders due to expire this week, with banks preparing to repay 225 billion euros of 12-, six- and three-month funds on Thursday, may affect the euro.
If the results highlight more banking sector troubles, traders may turn cautious on the euro, though other analysts say a withdrawal of funds from the banking system will boost lending rates and provide support for the single currency.
Latest data from the Commodity Futures Trading Commission showed currency speculators moved to a net long position in the euro for the first time this year. [IMM/FX]
Graphic on latest FX positioning r.reuters.com/kus26k ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The dollar index =USD.DXY, a measure of its performance against six major currencies, was little changed at 79.44 after dropping to 79.25 on Friday, its lowest in almost eight months. It fell through the 61.8 percent retracement of its rally from November to June on Friday, a bearish signal.
The dollar steadied against the yen above 84 yen JPY= as selling by Japanese exporters and institutional investors ahead of the fiscal half-year end was offset by wariness of more yen-selling intervention by Japan.
It held above a post-intervention low of 84.12 yen hit on Friday and more than a yen above the 15-year low of 82.87 hit shortly before Japanese authorities acted nearly two weeks ago to sell yen for the first time in six years.
The dollar rose on Friday on rumours of further yen-selling action but gave up the gains. Prime Minister Naoto Kan said he was unaware of any new market intervention. [ID:nN24270952]
Bank of Japan Governor Masaaki Shirakawa said on Monday the central bank would examine the impact of the yen's rise at its next policy-setting meeting next week and was watching forex moves with great interest. [ID:nTKX007009] [ID:nTKX007008]
Data on Monday showed Japan's annual export growth slowed in August for the sixth successive month, underlining concerns about yen strength. [ID:nTOE68Q01M]
Traders expect the dollar to remain on the back foot after the U.S. Federal Reserve last week signalled it could loosen monetary policy further to support a sluggish economy.
"The market will continue to sell dollars into the (Fed's) November meeting on expectations of more easing," said Lee Hardman, currency economist at Bank of Tokyo-Mitsubishi UFJ.
"That will also continue to support equities and commodity prices."
Some traders said the dollar picked up from initial weakness after Chinese authorities lowered its mid-point against the yuan after nine days of higher yuan fixings. [ID:nTOE68Q034]
The Australian dollar hit a two-year high of $0.9623 before trading flat on the day at $0.9590 AUD=D4.
(Graphics by Scott Barber)