(Corrects percentage drop in first paragraph to 19 months from 18 months, and percentage drop in FTSEurofirst in second paragraph and headline to 15 months from seven months)
* FTSEurofirst 300 ends 2.4 pct lower, hits 6-week low
* Disappointment following lack of details on ECB's ABS plan
* Banking, energy sectors feature among top decliners
By Atul Prakash
LONDON, Oct 2 (Reuters) - European shares fell sharply on Thursday, with Italy's benchmark index recording its biggest one-day percentage drop in 19 months, after the European Central Bank gave fewer details than the market had expected about its plan to buy secured debt.
The pan-European FTSEurofirst 300 index closed 2.4 percent lower at 1,335.11 points, the biggest percentage drop in 15 months, while Italy's FTSE MIB index fell 3.9 percent to 19,894.88 after the ECB's announcements.
The central bank would begin to buy covered bonds (CB), a form of secured debt, from banks in mid-October and purchase asset-backed securities (ABS) at some point in the fourth quarter of the year, ECB President Mario Draghi said, despite misgivings in Germany and elsewhere.
"Draghi confirmed that purchases will take place at least over the next two years, but disappointed investors by not confirming the size of purchases. Overall, today's ECB meeting confirms that the governing council is now in wait-and-see mode," Azad Zangana, European economist at Schroders, said.
The planned moves are an attempt to kickstart a languishing euro zone economy after cutting interest rates last month. The ECB left its main refinancing rate at 0.05 percent on Thursday.
The ECB hopes the programme will spur a market for such credit and support lending to the small- and medium-sized firms that form the backbone of the euro zone economy, but equity investors remained sceptical.
"Investors had hoped for more than they got. The fact is that the euro zone is in a liquidity trap in which additional monetary policy measures just aren't working," said Jeremy Batstone-Carr, head of private client research at Charles Stanley.
"The banking sector has weakened notably as ABS/CB purchases are to be caveated, probably in a nod to Germany where opposition to the deterioration in the quality of the ECB balance sheet is well known."
Banks featured among the worst decliners, with the euro zone banking index down 4.1 percent, the biggest percentage drop in 15 months. Societe Generale, Unicredit , Intesa Sanpaolo and Banco Popular all fell between 4.8 and 5.9 percent.
The European oil and gas index was also hit hard, down 4 percent, with investors nervous following a sharp fall in oil to a 27-month low on concerns of a supply glut.
The FTSEurofirst 300 index, which is up just 1.6 percent this year, has fallen more than 5 percent since mid-September, when it climbed to its highest since early 2008.
The market has been 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 rate hike next year.
Friday's non-farm payrolls data, which is likely to show that the U.S. jobs market is improving, could strengthen the case for a rate hike.
Among other big movers, Kinnevik slumped 8.2 percent after shares in Rocket Internet plunged 13 percent on the day of their stock market debut in Frankfurt. Kinnevik owns around 14 percent stake in Rocket.
Rig firms Transocean and Seadrill fell 6.2 percent and 5.6 percent respectively, tracking peers that have taken a beating on lower oil prices, cutbacks in capex and an abundance of new rigs.
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 Alasdair Pal; Editing by Mark Trevelyan)