Marks & Spencer Group plc has ended its long-standing technology helpdesk contract with India-based Tata Consultancy Services Ltd., following a cyberattack that cost the U.K. retailer an estimated 300 million British pounds ($400 million), The Telegraph reported. Although Tata denied responsibility and said the breach occurred within Marks & Spencer’s own environment, the latter said the decision followed a standard review process and that the Indian outsourcing giant continues to handle other technology operations, including data center and cloud services.