* FTSE 100 falls 0.6 percent
* Banks, energy stocks fall
* Miners, Imperial tobacco gain
By Simon Falush
LONDON, Sept 22 (Reuters) - Weaker banks and energy stocks, weighed by nagging concern about the state of the U.S. economy, helped push Britain's top shares lower early on Wednesday.
By 0755 GMT the FTSE 100 was down 34.84 points or 0.6 percent at 5,541.35 after it fell 0.5 percent on Tuesday on nervousness ahead of the Fed's statement on monetary policy, published after London's close.
In the event, the U.S. central bank nudged the door wider to pumping more money into the economy but kept overnight interest rates unchanged near zero, as expected.
U.S. stocks initially popped higher after the Fed statement, but gave back those gains quickly and ended flat.
Some investors had hoped that with recent improvements in economic data, the Fed would issue a more upbeat outlook or clarify the measures it would take to stimulate demand.
Banks, which tend to be sensitive to even slight shifts in risk appetite, were the biggest drag on the index, with Lloyds Banking Group off 2 percent and HSBC 0.6 percent weaker.
"There is concern out there, the recovery is weaker than markets would like," said Phil Poole, global head of macro investment strategy at HSBC Global Asset Management.
"There's a tension between evidence of weakness (in the U.S. economy) and the fact that there will be a liquidity comfort blanket from the Fed."
Energy stocks retreated as fears on the demand outlook weighed on the sector. BP and Royal Dutch Shell fell 1.1 and 0.7 percent respectively.
Miners bucked the trend, however as metal prices firmed with gold hitting a record peak. Randgold Resources and African Barrick Gold added 2.3 and 2.1 percent respectively, while Rio Tinto added 1 percent.
Imperial Tobacco was the other standout gainer, adding 1.5 percent after it said its key global cigarette brands continued to perform well and announced volumes in line with its expectations.
MPC WATCH
After the focus on U.S. monetary policy, UK investors will switch their attention to the domestic outlook for interest rates with the release of minutes from this month's Bank of England Monetary Policy Committee meeting.
Economists expect minutes to the BoE's Sept. 8-9 MPC meeting to show that Andrew Sentance remained the sole advocate of higher interest rates for a fourth successive month.
Across the Atlantic, after Tuesday's Federal Reserve meeting, investors will have the latest weekly U.S. mortgage and refinancing indexes to assess this afternoon, together with the July FHFA Home price index.
Among stocks in retreat, Weir Group fell 2 percent after RBS cut its rating on the stock to "hold" from "buy" on valuation grounds.
Ex-dividend factors clipped 1.19 points off the FTSE 100 index on Wednesday, with Aggreko, Aviva, and Petrofac all losing their payout attractions. (Editing by Hans Peters)