The Economic Sentiment Indicator declined to 94.7 points at the end of January, from 95.3 a month earlier, the Commission said in its latest business and consumer survey.
Confidence in the Romanian retail sector fell 1.2 points to minus 1.3 in January, while confidence in the construction segment slid to minus 31.4 points, from minus 30.5 points in December.
Industry confidence decreased 1.1 points to minus 3.1, but confidence in services rose to minus 0.2 points, from minus 1.9 points in the previous month.
Consumer confidence inched up to minus 34.3 points, from minus 34.8 points at the end of December.
In the EU, the economic sentiment indicator increased 0.9 points to 104.7 points, the highest level since June 2011. Business sentiment in the euro area rose for the ninth straight month to 100.9 points.