Turnover at Quinn Industrial Holdings - the packaging and construction business formerly owned by Sean Quinn - has grown 25% to €203m (£158m) in the last year, according to its latest results.
And the company, which employs around 700 people in Cavan and Fermanagh, also recorded pre-profits of €5.9m (£4.6m) - up from a loss of €14.6m (£11m).
It's the first full year of results for the company, which bought over parts of the Quinn business two years ago.
The business has been battling attacks on its property and on the property of some of its officials in recent weeks.
QIHL is led by Liam McCaffrey - a former close associate of Sean Quinn. But relationships have soured over Mr Quinn's desire to win back a share of the businesses.
Mr Quinn is neither a director nor shareholder in the business but is paid €500,000 (£388,000) as a consultant.
Speaking about the results, Mr McCaffrey said 2015 had been a "transformative year... stabilising and growing business and employment and restoring pride and confidence for the future".
A spokesman added: "The group is well positioned to take advantage of the recovering Irish economy as well as the strong and continued demand from the UK construction market."
QIHL was formed in 2014 and with the backing of American investors, bought Quinn's packaging and construction businesses from Aventas.
Aventas was the name given to the Quinn group of businesses after it was taken over by lender, Irish Bank Resolution Corporation (IBRC).
Quinn Industrial Holdings is 88% owned by the US investors through a Luxembourg firm and 22% by QBRC - the entity set up by businessmen John 'Bosco' O'Hagan from Co Londonderry, Ernie Fisher and John McCartin, a Fine Gael councillor.
The three jointly recently sent an internal email appealing for recent incidents of criminal damage to stop.
It follows a resurgence in attacks on businesses in Cavan and Fermanagh that used to be owned by Mr Quinn.
Workers at a wind farm have received a number of death threats, while cross-border police investigations are continuing into threats against Liam McCaffrey.
The email, which was signed by Mr Fisher, Mr O'Hagan and Cllr McCartin, implored "all parties to focus on rebuilding broken reputations, desist from criminal damage threats and defamation and look to a productive future".