Telecoms giant BT has denied dragging its feet over passing on big savings for customers calling a mobile phone.

The company blamed the delay on mobile phone operators, which it said had not given sufficient warning.

In a damning report in January, the Competition Commission accused the four main UK mobile operators (Vodafone, Orange, O2 and T-Mobile) of overcharging.

It ordered the operators to reduce the amount they bill one another for connecting calls - known as termination charges.

A one-off cut of 15 per cent came into force yesterday in a move predicted to save consumers £190 million a year in calls from a landline to a mobile between now and 2006.

BT says it will not be able to implement the savings for its customers until October 1, at the earliest, because of the time needed to update and test its software.

The delay, it said, was because the mobile operators had only confirmed details of the reduction in the past few days.

Pierre Danon, chief executive of BT Retail, said: "I am absolutely amazed that BT could even be accused of dragging its feet or trying to take advantage of this situation when we have behaved impeccably since the beginning of this issue and we will continue to do so.

"I personally guarantee that we will be passing all of the savings penny for penny on to our customers.

"This is something that we could have done much sooner had it not been for the mobile operators dragging their feet.

"All the favourable savings that will have been lost by our customers between now and October 1 will be passed back to them with additional special discounts."

BT say the price cut will save its customers £198 million by next July.

Yesterday's 15 per cent cut, which applies to calls made from a landline phone to a mobile and from one mobile to another, will be followed by further cuts of 14 per cent and 15 per cent, minus the rate of inflation, in the next three years.