U.S. general insurer Liberty Mutual will rebrand Quinn Insurance as Liberty Insurance next year after completing its takeover of the Irish-based insurer Monday.

We are pleased with this acquisition as it enables us to enter the Irish market as the economy begins to recover, David H. Long, Liberty Mutual's chief executive said in a statement.

Quinn Insurance, which has 275,000 customers, was put into administration last year after Ireland's financial regulator said it was not meeting solvency requirements.

Quinn Insurance's former owner Sean Quinn lost control of the firm and the rest of his empire after Anglo Irish Bank, recently renamed Irish Bank Resolution Corporation (IBRC), said he owed it up to 2.9 billion euros (2 billion pounds).

Quinn disputes the size of his debts to IBRC. Ireland's once richest man, with an estimated fortune of 4.7 billion euros, declared himself bankrupt in Northern Ireland's High Court on Friday with assets of less than 50,000 pounds.

Lawyers for IBRC said Monday it would be seeking an annulment of the bankruptcy declaration by the end of the week. IBRC wants to claw back as much money as it can from Quinn.

We will be making an application in the North to annul the insolvency proceedings as the courts there do not have the jurisdiction to deal with his bankruptcy, as his centre of main interest is not the North, Paul Gallagher, a lawyer for IBRC, told Dublin's Commercial Court.

Liberty Mutual acquired 51 percent of Quinn Insurance earlier this year and will run the group. IBRC retains a 49 percent stake.

Ireland's state-run Insurance Compensation Fund is paying Liberty Mutual 738 million euros to take over Quinn Insurance funded by a levy on insurance policyholders.

The government has said the alternative to the takeover of Quinn Insurance would be its liquidation at a cost of up to 1.3 billion euros.

Liberty Mutual in Ireland will be run by Patrick O'Brien, a former chief operating officer of Liberty Mutual Insurance Europe.

(Reporting by Carmel Crimmins)