Preliminary figures for economic growth show a marginal decrease of 0.1% in July, August and September of this year compared to the second quarter of the year.
The Central Statistics Office said the figures for Gross Domestic Product show the "small decrease was mainly driven by contraction" in the multinational sector.
Earlier this year a surge in exports, particularly driven by pharmaceutical companies hoping to get ahead of the imposition of US tariffs, resulted in a 7% increase GDP in the first three months of 2025.
Many observers had expected that trend would taper off in the second half of the year.
However, CSO senior statistician Kieran Culhane said the broad picture was "flat" as there was still a lot of activity among information, communications and technology companies.
GDP is estimated to have risen by 10.5% when compared to the third quarter of 2024.
The CSO preliminary figures for GDP are subject to revision and Mr Culhane said there needed to be "a bit of caution" around the figures.
The Government has long cautioned against using GDP to accurately measure economic growth as it is routinely distorted by multinational activity. Its preferred measure, modified domestic demand (MDD), is not included in the CSO's early estimates.
Commenting on today's CSO figures, EY Ireland's chief economist Dr Loretta O'Sullivan said that while early GDP estimates for Ireland are volatile and liable to revision when full details become available, the flash for the third quarter of 2025 is in the expected direction.
"The soft quarter-on-quarter reading reflects a slowdown in the multinational-dominated industrial sector and comes as no great surprise," Dr O'Sullivan said.
"US tariff front-running by pharmaceutical companies boosted exports and GDP earlier in the year, but this activity is now unwinding. It's clear the domestic economy is holding its own, with today’s retail sales data pointing to solid consumer spending in September," she added.
