Supermarket chains Tesco, Morrisons and Asda lost out to upmarket rivals and discounters as the UK grocery market expanded at its slowest rate since 2005 in the last three months.Market growth slowed slightly to 2.4% in the 12 weeks to February 2nd, according to figures from retail researchers Kantar Worldpanel.Tesco and Morrisons, who have both struggled to boost sales as consumers continue to rein in spending, both lost market share in the period as a result of declining sales, Kantar said.Wal-Mart-owned Asda managed to grow, with sales up 0.5% compared with a year ago, but lost share after failing to match the overall market growth.Tesco unsurprisingly reflected the slow overall market with sales down by 0.4% compared with the same period last year, Kantar said.Figures out today from the British Retail Consortium showed food sales took a hit last month as the housing recovery and New Year sales encouraged people to spend more on household items and clothes instead.Kantar said the sector's winners included Sainsbury's, whose year-on-year growth of 2.7% was enough to boost its market share to 17.1% from 17% a year ago.Sales at Waitrose, part of the staff-owned John Lewis Partnership, rose 5.6% compared with a year ago, helping it to lift its share of the market to 4.9%.Double-digit sales growth helped Aldi and Lidl to gain market share, as cost-conscious shoppers increasingly use them for the weekly shop rather than making occasional visits.Aldi and Lidl together now account for 7.3% of sales, up 1.3% percentage points from last year. Kantar Retail Analyst Fraser McKevitt said: "Brighter economic prospects are yet to be seen in the nation's shopping trolleys. The slowest industry growth since 2005 made it hard for many of the biggest retailers to increase sales. However, shoppers felt the benefit as grocery inflation fell to only 2.1%."PW