NAPLES Italy (Reuters) - The European Central Bank on Thursday outlined its plans to buy secured debt, part of wider plans to encourage banks to lend more and bolster the flagging euro zone economy. ECB President Mario Draghi told a news conference the bank would be ready to start purchasing covered bonds in mid-October and asset-backed securities in the fourth quarter of 2014. The programs will last for at least two years, Draghi said, and taken together with the ECB's new targeted long-term loans to banks, "these purchases will have a sizeable impact on our balance sheet". "The new measures will support specific market segments that play a key role in the financing of the economy," he added. Draghi did not give a figure for the programs, full details of which will be released by the ECB later on Thursday. Following disappointing initial take-up at last month's first offering of TLTROs, Frankfurt's efforts to restart the market for asset-backed securities have come into sharper focus. Many question, however, whether the small market for this kind of reparceled debt in Europe, which some analysts say could be as little as 250 billion euros, can play a decisive role in turning around lending in the bloc. Asset-backed securities are built by banks pooling loans given to companies or consumers to buy homes, cars or credit cards. They are then sold onto other banks but increasingly to insurers, pension funds or now even the ECB. Covered bonds are similar instruments but the underlying assets, such as apartment blocks, are ringfenced so if the bank goes bust, the assets are still there. That makes them safer than ABS where the underlying loans are not ringfenced. The ECB hopes that by buying the loans, it can spur the banks into giving further such credit, safe in the knowledge that it can be spun off afterwards. Draghi had appealed to governments to back the initiative with state guarantees, a step that would add a seal of security to the market and encourage other buyers. But France and Germany oppose such state guarantees, opposition that will further dampen the ECB's bid to grow the small market. (Reporting By John O'Donnell Editing by Jeremy Gaunt)