BRUSSELS: Industrial output in the euro zone fell slightly in January, official data showed on Thursday, though longer term data offered reassuring signs of improvement in the struggling European economy.

The EU's Eurostat agency said industrial production in the 19-nation currency bloc dipped by 0.1 percent in January from a month before, despite expectations of a slight rise over the period.

However, over 12 months, production in the euro zone gained 1.2 percent in a sign that economic activity in Europe could be slowly recovering from lackluster growth levels on the back of cheaper oil and unprecedented policies from the European Central Bank.

Reassuringly, factory output in France, the bloc's second biggest economy and an increasing source of worry, grew by a solid 1.6 percent over 12 months, exceeding Germany's 1.0 percent.

Post-bailout Ireland roared ahead by 8.8 percent, though Portugal, also after an EU-IMF bailout, fell by 1.8 percent.

The biggest concern remained Italy, the euro zone's third biggest economy and currently in recession, where production fell by an alarming 2.2 percent over a year.

Meanwhile, a leading dissenter from the European Central Bank's trillion-euro stimulus says the program wasn't needed to ward off chronic deflation and takes the pressure off governments to carry out key budget and economic reforms.

Jens Weidmann, the head of Germany's national central bank and a member of the ECB's 25-member governing council, said Thursday it "was not necessary to further loosen monetary policy through large-scale bond purchases."

Speaking at the Bundesbank's annual news conference, Weidmann said there was little evidence that negative inflation rates were becoming entrenched in a downward spiral that could kill off growth and jobs. He said low oil prices have played a major role temporarily in pushing consumer prices lower but that long-term inflation expectations remained steady.

The ECB this week started buying government bonds with newly created money, a step aimed at raising inflation and stimulating growth. It hopes to raise annual inflation rates closer to its goal of just under 2 percent, against the current minus 0.3 percent.

The ECB bond purchases have driven bond prices up and interest yields down, since price and yield move in opposite directions. That has meant lower borrowing costs for governments.

"If the member states get used to such financing conditions, it could lead to a lessening of their motivation for further consolidation or reform measures," Weidmann said.

The euro zone is still recovering from a crisis over too much government and bank debt in some countries. Greece, Cyprus, Ireland and Portugal all needed bailouts from their euro zone partners and the International Monetary Fund to help them finance their debts. Spain also got help to shore up its banks.

The ECB's stimulus program has sent the euro lower, which should be positive for the euro zone economy, while stocks have risen. Weidmann cautioned that it was far too early to judge the success of the program after only several days of purchases and that the program's risks needed to be considered.

The ECB will buy 60 billion euros a month through at least September 2016, amounting to 1.1 trillion euros ($1.2 trillion).

Weidmann also described as "problematic" the decision to let France take more time to bring its deficit in line with euro zone rules. He said rules limiting overspending were one of the foundations of trust in the shared currency.

In the euro zone, the national central banks of member countries are networked under the European Central Bank and their heads sit on the ECB's top decision-making body. So even though Weidmann disagrees with the stimulus program, the Bundesbank is participating by purchasing German government bonds.