It is also introducing a new three-year fixed rate for green mortgages, with rates from 3.80pc for new customers.
However, existing PTSB customers coming off fixed rates will not be able to apply for the new green rate or the lower four-year fixed rate.
The four-year fixed rate is coming down by 0.30 percentage points. This is the second reduction to the bank’s four-year fixed rate, which was last cut in December.
The new four-year fixed rates come into effect from today and will be priced at 3.80pc, 3.90pc or 4.05pc, depending on the loan-to-value of the mortgage.
PTSB said the reduction would save up to €44 a month for a customer fixing a mortgage of €250,000 over a 30-year term.
The lender is also launching a new three-year fixed-rate green mortgage product for new customers.
This has rates from 3.80pc to 4.35pc, depending on the mortgage amount and the loan-to-value of the mortgage. It is available now.
PTSB said its green mortgage is a key feature of its sustainability strategy and offers customers a lower interest rate where their mortgage was secured on a home with a Building Energy Rating Certificate (BER) of A1 to B3.
The bank said the new rates built on its already successful five-year fixed-rate green mortgage product, which is available to new and existing customers and accounted for 30pc of the bank’s total new mortgage lending in 2023.
Broker Michael Dowling, of Dowling Financial, said he was disappointed to see PTSB discriminating between new and existing customers.
“Other lenders don’t discriminate between new and existing customers – I thought we had moved away from that,” he said, adding that charging different rates was not a good way of attracting business.
He added that PTSB was cutting its rates because they were not competitive and it was losing out to its rival lenders.
This was particularly the case on green rates, where Bank of Ireland, EBS and AIB were attracting more mortgage business.
Mr Dowling said PTSB’s share of the new mortgage market had fallen to around 15pc or 16pc, while it had previously been as high as 20pc.
In the last two weeks, PTSB reported an underlying profit before tax for 2023 of €166m, compared with €45m in 2022, boosted by its new former Ulster Bank loans.
The bank pointed to strong income growth throughout the year, with net interest income up 71pc year-on-year, but the market reacted badly as shares fell 12.5pc.
PTSB’s total performing loan book stood at €20.9bn at the end of the year, €1.8bn higher than at the end of 2022.
This growth was driven by business banking and consumer finance, which offset a decline in new mortgage lending.