The telecommunications regulator Ofcom has announced new controls on charging, imposing limits on the amount mobile network operators (MNO) can charge other phone companies for connecting calls on their mobile networks.

In the next four years, the mobile companies are predicted to save £400-500 million from the change - and Ofcom says it expects the savings to be passed on to customers.

The charge controls will apply for four years from 1 April. They will be put in place in a number of stages between then and 2011.

You can view further details of the changes at Ofcom's website.