* FTSEurofirst 300 up 0.1 percent
* Strong underlying results from BP support oil majors
* Cautious trade expected ahead of Fed decision on Wednesday
By Harpreet Bhal
LONDON, Nov 2 (Reuters) - European shares edged up on Tuesday with oil majors supported by upbeat underlying results from BP, though trade was choppy ahead of the U.S. Federal Reserve's decision on monetary easing on Wednesday.
By 1003 GMT, the pan-European FTSEurofirst 300 index of top shares was up 0.1 percent at 1,089.48 points in choppy trade on low volumes of just 23 percent of the index's average 90-day trading volume.
Investors were reluctant to take on large positions ahead of a two-day Fed meeting, ending on Wednesday and widely expected to include an announcement of further quantitative easing measures, and U.S midterm elections which could alter the balance of power in the House of Representatives.
Banks were lower, with Barclays, BNP Paribas and Commerzbank off 0.4-0.6 percent.
Despite widespread expectation the Fed will resume a programme of large-scale asset purchases to spur economic recovery, uncertainty lingered over how much it will eventually spend -- with dealers expecting asset buying of $80-$100 billion per month.
"The markets had a good run anticipating QE (quantitive easing) and the issue is how much they (Fed) commit to doing upfront," said Bernard McAlinden, investment strategist at NCB Stockbrokers in Dublin.
BP rose 1.8 percent as investors focused on a forecast-beating rise in underlying profit, looking beyond an increased estimate of the likely cost of its Gulf of Mexico spill to $40 billion which dented third-quarter results.
BP shares have fallen 28 percent this year, against a 5.9 percent rise on the FTSE 100 in the same period.
"This underperformance... may mean that the shares have already taken the brunt of the pressure. As such, the market consensus is that BP remains a buy for the longer term," Richard Hunter, head of UK equities at Hargreaves Lansdown said.
Within the energy sector, BG Group added 2.1 percent after the gas producer posted a 12 percent rise in third-quarter net profit and significantly upgraded its Brazilian resources.
EUROZONE FACTORIES PICK-UP
Helping to bolster positive sentiment, a business survey showed euro zone manufacturers boosted output in October at a faster pace than previously estimated, with Ireland and Spain both recovering while Greece continued to struggle.
Industrial goods companies Prysmian, Schneider Electric and Siemens added 0.4-0.8 percent.
The Markit Eurozone manufacturing Purchasing Managers Index (PMI) followed strong U.S. manufacturing growth data on Monday, which helped boost confidence in the pace of economic recovery.
"It won't be bad news ...if the Fed were to disappoint in how much they commit to right now if that is against the backdrop of strong data. If the data is strong we do not need QE," McAlinden said.
In contrast to the Fed's expected monetary easing measures, the ECB was seen sticking to its exit path when meeting on Thursday, on the view that the euro zone's recovery has enough momentum to ride out any bumps in the road in the months ahead.
Among other movers, Dutch chemicals group DSM fell 3.9 percent after reporting third-quarter operating profit at the low end of estimates, ending a run of positive earnings surprises. (Editing by Dan Lalor)