NI exports to the Republic rise, while GB sales fall
Exports from Northern Ireland to the Republic of Ireland rose by £540m, while sales to the UK fell by £2.9bn last year, according to latest figures.
It is understood the closure of the JTI cigarette factory in Ballymena was a major factor in the decline of GB sales.
However, Great Britain remains Northern Ireland's biggest external market, with total sales of £11.3bn
Ireland is the biggest export market, with sales of £3.9bn.
Statistics published by the Northern Ireland Statistics and Research Agency (Nisra) show that sales to Great Britain are down 20.2% in 2017.
Nisra said the annual decline in sales to Great Britain is driven by "a substantial decline" in the food, beverages and tobacco subsector.
Last year, cigarette maker JTI Gallaher shut its factory in County Antrim with the loss of more than 800 jobs.
Export increases and decreases
In total, Northern Ireland's external sales was estimated to be worth £21.4bn in 2017, a 10.1% (£2.4bn) drop over the year in current prices.
Exports to the EU, excluding exports to the Republic, fell over the year by £269m (12.1%) to £2bn.
Exports to the rest of the world, which are all countries outside the EU, increased by £195m to £4.3bn.
The latest trade figures also show that sales within Northern Ireland received a £1.3bn boost to £45.2bn, up by 2.9% over the year to the highest level on Nisra survey's record.
Overall, total sales (including external sales) from Northern Ireland companies dropped by 1.7% (£1.1 billion) in 2017 to £66.6bn.