The euro rallied on the news, rising 0.69 per cent against the pound to £0.84825, and up 0.44 per cent against the dollar, to $1.1288.
The interest rates on the marginal lending facility and the deposit facility will remain unchanged at 0 per cent, 0.25 per cent and minus 0.4 per cent respectively. The governing council said it continues to expect the key ECB interest rates to remain at present or lower levels for an extended period of time, and well past the horizon of the net asset purchases.
The governing council also reconfirmed that it will run its monthly asset purchases of €80bn (£68bn) until March 2017.
Extending the quantitative easing programme beyond this point would be "far more complicated" than it seems due to the availability of qualifying assets, according to Craig Erlam, senior market analyst at Oanda.
"The problem is believed to centre around the amount of qualifying German debt available for the ECB to purchase," Erlam said.
"In order to resolve the problem, the criteria needs to be adapted or the deposit rate cut, which would temporarily increase the amount of debt available for purchase and may then enable the program to be extended."
Meanwhile, Naeem Aslam at ThinkMarkets accused the central bank of "dithering". "The action assures that the central bank is still committed in its action, but does need a lot of tail wind from fiscal side," he added.
"We suspect that the ECB will end up going further down the quantitative easing road, very possibly before the end of 2016," said Howard Archer, at IHS Markit.
"We suspect that the ECB will extend its asset buying programme by a further six months to September 2017, or beyond. There also has to be a very real possibility that the ECB will end up lifting the monthly purchases from €80bn, although this seems less likely than an extension."
Archer added: "We remain very doubtful that the ECB will take interest rates any lower with the deposit rate already at minus 0.40 per cent. While the ECB has indicated that interest rates could possibly go lower, there is clearly heightened concern over the impact that negative/low interest rates are having on Eurozone banks.