Market researcher Kantar Worldpanel said all 10 major retailers were in growth for the first time in three-and-a-half years. Grocery prices jumped 2.6 percent year-on-year in the period, up from the 2.3 percent recorded in the 12 weeks to March 26.

Market leader Tesco (>> Tesco PLC) posted growth of 1.9 percent while Sainsbury's (>> J Sainsbury plc) grew by 1.7 percent, Asda grew by 0.8 percent and Morrisons (>> WM Morrison Supermarkets PLC) grew by 2.2 percent. Asda's growth marked the first year-on-year sales rise since October 2014.

The results were boosted by the timing of Easter, which fell later than normal this year.

(Reporting by Kate Holton, Editing by Paul Sandle)