Bank of Ireland remains the market leader with a mortgage book of 22bn, followed by Permanent TSB with 20.5bn.

AIB is in third place at 18bn with its focus on selling to existing customers rather than reaching new borrowers through mortgage brokers.

Ulster Bank and First Active have a combined mortgage book in the Republic of about 17.5bn.

After several years in the pipeline, the Irish Bankers' Federation finally published a detailed analysis last week of new mortgage lending over the past 18 months. It revealed that one in three new loans is a top-up of an existing mortgages, while first-time buyers account for only 18% of new home loans.

The IBF figures failed to analyse the 18.6bn in new mortgages in the first half of this year by lender, although it is understood that Permanent TSB led the field with a market share of just under 23%.

Banking sources say new business figures reveal little about underlying profitability because mortgages must be on a lender's books for several years before making a return. This is because of the expensive inducements paid to win the business, including brokers' commissions and introductory discounts.