Upmarket US grocer Whole Foods Market saw its losses mount to £14.2m in the UK last year despite a surge in sales as it benefits from shoppers’ hunt for better quality food.

Sales rose by 26% to £81.5m as the company opened one new store and enjoyed an 8.6% rise in sales in established outlets in the year to 29 September 2013, according to accounts for Fresh & Wild, the UK parent company. But pre-tax losses widened by 12.6% to £14.2m as head office costs increased and it opened a new store in Cheltenham in 2012 and prepared to open outlets in Richmond and Fulham last year.

As it celebrates a decade of trading in the UK, the retailer famed for its organic and health foods has now racked up losses topping £100m in the UK since it acquired Fresh & Wild branches in 2004 and launched its first Whole Foods outlet in Kensington, west London, in 2007.

Jeff Turnas, UK regional president, said: “We are pleased with our healthy (established) store sales growth, which we believe highlights the increasing awareness of the Whole Foods Market brand and demand for the differentiated shopping experience we offer.  We expect our investments to deliver strong returns over the long term.”

Whole Foods appears to be benefiting from an increasingly divided market for groceries in the UK in which upmarket grocers including Marks & Spencer and Waitrose as well as discounters such as Aldi and Lidl are seeing strong growth while mid-market grocers, particularly Tesco and Morrisons are coming under pressure. Whole Foods’ ultimate parent company, which began as a single store in Austin, Texas, in 1978, has said it is committed to investing in the UK despite problems in its home market where sales growth is slowing in the face of increasing competition.