Sean Quinn, an Irish property mogul who parlayed a gravel pit into a sprawling business empire, on Friday declared bankruptcy in a Belfast court, unable to pay the €2.8 billion he owed to a troubled lender that Ireland nationalized in 2009.

By declaring bankruptcy in Northern Ireland, which is part of Britain, Mr. Quinn will have to wait only a year before he can start another business — a more lenient standard than in Ireland, where the waiting period is 12 years.

Mr. Quinn, 64, sharply criticized the Irish bankers who presided over Anglo Irish Bank, whose toxic debts were taken over by a state-backed “bad bank,” the National Asset Management Agency, and transformed into the Irish Bank Resolution Corp. that is now pursuing him for unpaid loans.

“I am certainly not without blame,” he said Friday. “I am not in the business of pointing fingers or making excuses.”

“However,” he added, “recent history has shown that I, like thousands of others in Ireland, incorrectly relied upon the persons who guided Anglo and who wrongfully sought to portray a blue-chip Irish banking stock.”

A court spokesman confirmed that the court had declared him bankrupt, Reuters reported.

Once dubbed the “Mighty Quinn,” Mr. Quinn started a gravel quarry on his father’s farm in 1973 and built it into the Quinn Group, an international conglomerate with interests in cement, plastics and glass, insurance and hospitality. He resigned from the company’s flagship, Quinn Insurance, in 2008 after the insurer was fined for breaching financial rules.

His fall came after he secretly invested in derivatives based on shares in Anglo Irish Bank, a strategy that went sour in 2008. These “contracts for difference,” or C.F.D.’s, enabled Mr. Quinn to bet on the bank’s shares without buying them outright, meaning he could win huge tax-free profits or take enormous losses.

Since then, Mr. Quinn and his family have taken legal action to contest the validity of his bank debts, arguing that the €2.8 billion, or $3.9 billion, was lent for the “illegal purpose” of propping up Anglo’s own share price.

With the bankruptcy filing, Mr. Quinn and the bank intensified their ongoing struggle. The bank is now evaluating Mr. Quinn’s residency and bankruptcy claim in Northern Ireland.

Mr. Quinn said he made the bankruptcy application in Northern Ireland because “I was born, reared and worked all my life in County Fermanagh.”

For years, Mr. Quinn shunned the limelight, living with his wife near the landmark Slieve Russell Hotel, which he owned. But while declaring bankruptcy, Mr. Quinn expressed some regrets about that strategy.

“I have never sought publicity,” he said in his statement. “Sadly, this now seems to have worked very much to my disadvantage, especially when compared with the sophisticated and massively expensive publicity campaign operated for and on behalf of Anglo.”