* Pan-European FTSEurofirst 300 index down 0.9 percent
* Nexans, Sainsbury drop after warning on sales outlook
* Greek banks among top gainers
By Atul Prakash
LONDON, Oct 1 (Reuters) - European shares slipped on Wednesday following disappointing regional manufacturing data and on concerns about European earnings after retailer Sainsbury and cable maker Nexans issued sales warnings.
The pan-European FTSEurofirst 300 was down 0.9 percent at 1,367.50 points by 1416 GMT after German data showed manufacturing activity shrank for the first time in 15 months in September. Euro zone manufacturing growth slowed further as new orders contracted for the first time in a year.
"The prospect of a growth impulse in the euro zone is getting more distant as the economic data for Germany point to low to zero growth," Ronny Claeys, senior strategist at KBC Asset Management in Brussels, said.
Analysts said that subdued manufacturing activity from the region, coupled with Tuesday's figures showing a slowdown in euro zone inflation, will add pressure on the European Central Bank, which meets on Thursday.
"Once again, the central bank will have to convince investors that it has the firepower to stave off deflation risks," Barclays France director Franklin Pichard said. "We'll wait for Thursday's ECB meeting before buying the market."
The market also came under pressure following a sharp decline in some individual shares.
French cable maker Nexans tumbled 8.9 percent after saying full-year revenue would be flat, while British retailer J Sainsbury dropped 6.6 percent after cutting its full-year sales target and saying its strategic review would include future dividend policy.
"Sainsbury's share price has worsened considerably of late ... as an ongoing result of the increasing competition from the discounters. The market remains unconvinced on its prospects and the consensus now comes in at a weak hold," said Richard Hunter, head of equities at Hargreaves Lansdown Stockbrokers.
European share indexes have been falling over the past two weeks, dragged down by a flurry of sales and profit warnings as well as by growing concerns over the timing of the U.S. Federal Reserve's expected interest rate hike next year.
"Since the Fed meeting on Sept. 17, we've seen a 'risk-off' trade, with the fixed income market playing its role of safe-haven while equities and commodities have been slipping in negative territory," said Gregory Raccah, head of quantitative strategies at YCAP Asset Management.
On the positive side, Greek banks featured among the top gainers in Europe, with Piraeus rising 5.2 percent and Alpha Bank up 3.4 percent. Sources said Greece had won a concession from the European Central Bank that could help its top four lenders pass the asset quality review.
Europe's largest online fashion retailer Zalando began trading up 12 percent on its Frankfurt debut, but pared gains to trade just above the offer price. Swedish investment firm Kinnevik, Zalando's biggest shareholder with a post-IPO stake of about 32 percent, fell 7.9 percent.
Europe bourses in 2014: link.reuters.com/pap87v
Asset performance in 2014: link.reuters.com/gap87v
Today's European research round-up (Additional reporting by Blaise Robinson in paris; Editing by Robin Pomeroy)