(Sharecast News) - German discounter Aldi is to invest £900m boosting its UK presence next year, the grocer confirmed on Monday, despite seeing a dip in annual earnings.

The privately-owned business said sales in the UK and Ireland in the year to 31 December had risen 5% to £19bn, a record. However, operating profits were largely flat, easing to £432.9m from £435.5m, as margins ticked down 0.1 percentage point to 2.3%.

Aldi attributed the subdued earnings to ongoing investments in prices, infrastructure and pay.

However, looking forward and Aldi confirmed it would continue expanding its UK footprint, with €900m due to be invested in 40 new stores as well as distribution centres next year. The chain, which currently trades from 1,092 British stores, is targeting 1,500 UK stores over the long term.

Aldi also said it would continue trimming prices, with £340m spent cutting the cost of around 1,000 products so far this year.

Giles Hurley, Aldi UK and Ireland chief executive, said: "The cost of food remains one of the biggest pressures on households across the country. We're working hard to make good food more affordable for every family - cutting prices on everyday essentials [and] signing long-term supplier agreements to help home-grown production."

Aldi and smaller German rival Lidl, which is also privately owned, have boomed in recent years. Known for their limited but cheap ranges, both have seen their market share climb amid ambitious expansion plans, with Aldi's now standing at 10.6%, according to recent Kantar Worldpanel data, and Lidl's at 8.7%.