PwC's Northern Ireland economic outlook said this was despite overall unemployment having fallen by more than 10,000 since June 2014.
It said poor productivity remains the single biggest challenge to Northern Ireland's sustained recovery.
PwC's Esmond Birnie said the pace of recovery was "decelerating".
"Over the past seven months business confidence has been mixed, sometimes negative but always lagging the GB regions," Mr Birnie, who is PwC's chief economist in Northern Ireland, said.
"There have also been recent mixed messages around consumer confidence, with June 2015 seeing the first rise in unemployment for more than two years; this may simply be a blip - or it may be indicative of a deeper malaise.
"Currently, Northern Ireland's output is still 8% below the pre-crisis peak of 2008 and is something of a two-speed economy with employment contracting in public sector and financial services but growing fairly rapidly in advanced manufacturing, pharma, food processing and tourism.
"PwC forecasts that Northern Ireland's economic growth will remain the lowest of the 12 UK regions at around 1.8% in 2015 - lower than the 2.2% growth experienced in 2014 - and will fall again in 2016 to around 1.7%."
The report said that Northern Ireland's unemployment claimant count increased by 200 between May and June, the first month-on-month increase since December 2008.
It said that 62% of those registered as unemployed have been out of work for more than 12 months, while 19.7% of young people aged 18-25 are unemployed - well above the UK average of 13.2%.
PwC said the recent budget "confirmed that welfare reform and austerity will continue and that Northern Ireland probably faces a further four years of challenging economic circumstances, particularly around public spending".
Northern Ireland's economic growth will remain the lowest of the 12 UK regions in 2015, a new report has said.