"After 20 years of trading, our current consumer contract with Dixons Carphone expired on 31st March 2020," said the operator owned by Spain's Telefonica.

"While we've worked hard over the past year to put a number of options on the table, it has not been possible to reach a new agreement as they've made clear to the market that they wish to take a new strategic direction and change the relationship they had with mobile operators."

Dixons Carphone said on March 17 that it would close all 531 UK standalone Carphone Warehouse stores and shed 2,900 jobs as part of a plan to turn around its loss-making mobile phones business.

Dixons Carphone said it is moving to a "more flexible and transparent mobile offer that gives better value and choice" and which is scheduled to launch this year.

"We continue to offer our customers a wide range of choice through our own Mobile Virtual Network Operator, iD Mobile, and partners EE, Vodafone, Virgin Media and Voxi, including those who currently have an O2 connection," the company said in a statement.

(Reporting by Paul Sandle and James Davey; Editing by David Goodman)