British online supermarket Ocado Retail said revenue rose 39.7% in its first quarter to February 28, an acceleration from the previous quarter, on strong grocery delivery demand due to the pandemic. 

The joint venture between Ocado Group and Marks & Spencer said its revenue rose to £599m from £429m a year earlier. 

Revenue growth in the previous quarter was 34.9%. 

It said average orders per week increased 2.5% to 329,000, while the average order size was £147. 

Online's share of the UK grocery market has more than doubled over the year of the crisis, reaching 17% in February, according to market researcher Nielsen. 

"Millions of customers have experienced online grocery shopping through the pandemic and many of them will not be going back to bricks and mortar," Ocado's CEO Tim Steiner said. 

The first quarter is the last one before comparative numbers become considerably harder as the pandemic started boosting sales significantly from March 2020. 

Ocado aims to ramp up capacity over the course of 2021. Last month it opened one mini robotic warehouse, or Customer Fulfilment Centre (CFC), in Bristol and plans to open two standard-sized CFCs this year. 

A minimum of 12 new micro sites are being sought, primarily in London, to support the rollout of its Ocado Zoom fast delivery service. 

The group said it still expected positive revenue growth in its second quarter. 

While the company's shares are up 53% year on year, they have fallen 21% over the last month.

Analysts attribute this to a wider sell-off in the technology sector, a lack of new news regarding additional technology partnership deals and the increase in capital expenditure Ocado announced in its annual results last month.