Tesco has warned that the UK grocery sector faces an intensifying price battle in the run-up to Christmas, even as it raised its full-year profit forecast after winning market share over the summer. The UK’s largest supermarket group now expects to deliver annual profits of up to £3.1bn, £100m higher than previous guidance, after its decision to cut prices on 6,500 products by an average of 9% drew in more customers. Tesco said its grocery...