Northern Rock is increasing the rates on selected fixed rates, trackers and buy-to-let deals from the start of business tomorrow.
A spokeswoman for the lender says the move is a repositioning of its place in the market in terms of volume.
Selected two, three and five-year fixed rates are being increased by between 0.1% and 0.4%.
And all trackers and buy-to-let deals are rising by 0.1%.
Drew Wotherspoon, director of marketing at John Charcol, says the Northern Rock deals were sitting out on their own as highly competitive.
He says: “As a lot of other lenders have pulled their rates these were highly competitive and would have started to attract a lot of attention.”