Platform has cut the rates on two- and five-year fixed rate mortgages by up to 0.1 percentage points.
The intermediary arm of the Co-operative Bank is reducing rates on higher loan-to-value deals.
The lender offers a five-year fixed rate up to 90 per cent LTV at 2.34 per cent with a £1,499 fee.
A two-year fixed deal is available up to 85 per cent LTV at 1.54 per cent with a £999 fee or fee-free at 1.94 per cent.
Paul Norcott, head of mortgages at The Co-operative Bank, said: "These rate changes on higher LTV products, along with our recent move into Help to Buy, underline our commitment to helping brokers offer competitive deals for first time buyers.
"We continually review the products and rates we have available to ensure we’re listing mortgages our broker partners can recommend to their customers."
The provider has also cut rates on all five-year fixed rate buy-to-let mortgages by 0.05 percentage points. Deals now include a 2.44 per cent rate up to 65 per cent LTV with a £1,999 fee and £500 cash back, and a fee free product at 2.79 per cent up to 70 per cent LTV.
The move comes days after the lender introduced a range of Help to Buy mortgages, as the firm looks to grow its intermediary mortgage business.
Oliver Marley, head of mortgage research at Independent James, said: "Reducing rates at higher LTV is increasingly important, particularly for our London clients, as a 10 per cent deposit can amount to more than £40,000, which is a big stretch without the bank of Mum and Dad to help. It’s good to see that Platform can continue to support clients at this level."
