Sentix's index for the euro zone increased to 14.9 from 13.5 in the previous month. Analysts had on average expected the January reading to come in at 12.0, according to a Reuters poll.

A current conditions index rose to 16.3 in January from 13.3, the first increase since September.

An expectations index fell slightly to 13.5 from 13.8.

Sentix Managing Director Patrick Hussy said expectations were stabilizing at around the previous month's level due to the continued effects of supply bottlenecks and high inflation figures.

Sentix surveyed 1,163 investors from Jan. 6 to Jan. 8.

(Reporting by Miranda Murray; Editing by Riham Alkousaa)