The UK’s largest lenders have a three quarter market share but only provide 29 per cent, or 145, of the top 500 mortgages, according to Moneyfacts.co.uk.
The largest lenders offer six of the top 50 two-year fixed mortgages at 85 per cent loan-to-value, which equates to around 12 per cent.
They are most competitive in the two-year tracker market, but this still only equates to 48 per cent of top 50 deals.
The lenders used in Moneyfacts.co.uk’s research include Halifax, Cheltenham & Gloucester, Lloyds TSB Scotland, Santander, Alliance & Leicester, Abbey for Intermediaries, Nationwide Building Society, Woolwich, Royal Bank of Scotland, NatWest, Northern Rock, HSBC and first direct.
Moneyfacts.co.uk spokeswoman Michelle Slade says: “The figures show that biggest is not always best. In many cases the most competitive mortgage deals are not being offered by the largest mortgage lenders.
“Larger lenders appear to be concentrating on offering more competitive deals to borrowers with at least a 25 per cent deposit.”