Irish Life and Permanent has announced total after-tax profits of €411.2m, up 57% from €261.8m last year.
The profits surge was helped by record housing demand and an increase in new lending of 33%.
Total gross new mortgages issued in the Republic were €4.9bn, a 30% increase on the €3.8bn issued in 2003. Residential mortgage balances outstanding increased 20% to €14.5bn compared to €12.1bn at the end of 2003.
In the UK mortgage market, demand was strong in the "buy to let" sector in particular and mortgage balances in Capital Home Loans, the group's centralised mortgage lender which specialises in this area, increased by 49% to £2.8bn (€4bn) from £1.8bn (€2.6bn) in 2003. Gross new mortgages issued in 2004 were £1.3bn (€1.9bn), an increase of 47% over the 2003 level of £0.9bn (€1.3bn).
The 2004 outcome includes an exceptional profit of €21.1m, almost all of which relates to a profit achieved on the disposal of Irish Estates Management Limited.
Irish Life and Permanent boss David Went said: "On the back of the booming Irish economy, with continued job creation and record housing demand being particularly significant for our business, sales growth in all our business lines was extremely strong. New lending was up 33%, the value of life sales increased 17%, while investment inflows were ahead 23% to €1.6bn."
The contribution from the group's holding in insurer Allianz (Ireland) increased to €62.6m from €45.2m in 2003 reflecting a strong underwriting result in favourable market conditions.