The company, whose stock floated at 180p in July 2010, said growth was held back by capacity constraints.
Ocado said gross sales rose 16.9 per cent to £148m in the 12 weeks to 7 August – down from a 17.2 per cent lift in the second quarter.
It blamed the slower growth on its the lack of capacity at its Hatfield customer services processing centre, which is to receive an £80m revamp.
Ocado chief finance officer Andrew Bracey said: “We have a strong business but are giving a cautious outlook.” Meanwhile, chairman Michael Grade bought 83,000 shares in the company yesterday.
Ocado’s shares tumbled 11.44 per cent yesterday.