Online food retailer Ocado has announced a 12.3% increase in sales for the year ending 2 December 2018, although losses after tax soared from £9.8m to £44.9m.

Revenue grew to £1.59bn, up from £1.42bn in 2017, due to an increase in the average number of orders a week and partnership fees.

The widening losses were attributed to “continued investment” in the future, the increased depreciation charge from new distribution centres and the cost of new accounting measures.

Last year Ocado began to fulfil customer orders for Morrisons from its “state-of-the-art” facility at Erith.

Ocado ceo Tim Steiner said: “Our performance last year was the result of many years of focus, dedication and perseverance: what we have called our ‘18-year overnight success’.

“Our growth story, however, is only just beginning. We now have in place a platform for significant and sustainable long-term value creation as the leading pure-play digital grocer in the UK, a world-leading provider of end-to-end ecommerce grocery solutions, and as an innovative and creative technology company applying our proprietary knowledge to a range of challenges.”