Growth of euro zone money supply as measured by the broad indicator M3 slipped to 11.5% in December, according to the European Central Bank.
In November, the M3 indicator had stood at 12.3%.
The indicator covers cash, overnight deposits, other short-term deposits, repurchase agreements, shares and units in money market funds and debt securities with a maturity of up to two years.
It is the ECB's preferred indicator of medium-term inflationary trends in the euro zone economy.
The ECB's three-month moving average for M3 growth, which is less subject to volatility, showed a gain of 12.1% for October-December, up just slightly from 12.0% in the period from September to November.
Growth in lending to the private sector, another closely followed indicator, was unchanged in December 11.1%, an ECB spokesperson said.
