HMV is facing increasing competition in CDs from the supermarket chains but Giles disputed recent claims from Tesco that it had overtaken HMV in sales of chart CDs: 'We all know what our own market shares are, but not what the others' shares are. But we did raise our eyebrows at that claim from Tesco,' he said. Most recent figures for the whole CD market, rather than only chart titles, showed a 19% share for HMV against 6% for Tesco.