New figures from the Central Statistics Office show that cross-border trade in goods with Northern Ireland continued to sharply increase in the first nine months of the year.
Imports from Northern Ireland in the nine months from January to September increased by 60% to €2.822 billion compared to the same time last year.
Exports to Northern Ireland rose by 48% to €2.577 billion over the same period, the CSO added.
Today's CSO preliminary figures also show that seasonally adjusted goods exports inched 1% higher to €14.025 billion in September compared to August.
The CSO said that seasonally adjusted goods imports decreased by 4% to €8.310 billion.
This resulted in an increase of €468m (9%) in the seasonally adjusted trade surplus to €5.715 billion in September compared with the previous month,
Meanwhile, exports to Great Britain in September came to €1.412 billion, an increase of 36% compared with the same time last year.
The CSO said the value of goods exports to Great Britain in the first nine months of 2021 was €10.605 billion, an increase of 23% on the first nine months of 2020.
Imports from Great Britain grew by 2% to €1.456 billion the CSO said, while the value of goods imports from Great Britain for January to September 2021 dropped by 21% to €9.435 billion.

Today's CSO figures reveal that the EU accounted for €5.782 billion (40%) of total goods exports in September of which €1.456 billion went to Germany and €1.165 billion went to Belgium.
Total EU exports in September grew by 5% compared to the same month last year.
The US was the main non-EU destination accounting for 29% of total exports in September.
Meanwhile, the EU accounted for €2.401 billion (29%) of total goods imports in September, an increase of 16% on September 2020.
The UK with €1.749 billion (21%), the US with €1.614 billion (20%), and China with €766m (9%) were the main non-EU sources of imports, the CSO added.