By Jennifer Hill

LONDON (Reuters) - A quarter of lenders are yet to announce their mortgage rate intentions, five weeks on from the last interest rate cut by the Bank of England.

A total of 24 lenders have not yet said whether they will keep their standard variable rates (SVRs) on hold or reduce them, data from price comparison website Moneyfacts.co.uk shows.

Of those that have cut rates, 20 (28 percent) have passed on a reduction of less than the 0.25 percent cut in the base rate.

The Bank cut the official rate of interest by a quarter percentage point to 5 percent on April 10, the third cut since December.

Some lenders that have passed on the smallest cuts -- largely building societies -- already offer some of the highest SVRs on the market.

Saffron Building Society has said it will maintain its SVR at 7.15 percent and Earl Shilton Building Society has reduced its rate by just 0.05 percent to 7.35 percent.

Four others -- Northern Rock, as well as the Barnsley, Nottingham and Scottish building societies -- have cut their rates by just 0.10 percent, taking them from 6.94 percent at the Scottish Building Society to a high of 7.49 at Northern Rock.

Lenders have been scrapping cheap loans, failing to pass on reductions in the BoE base and tightening their lending criteria as they try to boost margins in the credit crunch fallout.