The monthly indicator fell back 0.3 points from November to December to stand at 101.38 with the medium to long term outlook advancing by 0.6 to close the year at 100.6.
The fall in the former indicator, designed to measure the economic outlook over the next four to eight months, had broken a run of rises that stretched back to August with the year ending on the same rate as July 2014.
Across the Eurozone, the OECD forecasts show “some signs of a positive move towards growth,” with Germany and Spain leading the way.
Italy returned evidence of “some improvements” after falling back in November whilst France remained unchanged with stable growth prospects.
In related news, Portuguese exports slowed to a growth rate of just 1.9 percent while imports grew 3.2 percent in 2014, increasing the trade gap to €10.56 billion, the Portuguese National Statistics Institute (INE) said on Monday.
The INE said that in 2013, exports grew at 4.5 percent, quite a lot more than imports which were at 0.9 percent leaving a trade gap of €925.8 million less than in 2014.
Excluding fuels and lubricants, exports increased 4.3 percent and imports 6.0 percent in 2014.