Waitrose is to open a dark store in west London in October to ramp up its London online delivery.

The site in Acton will be dedicated to online grocery picking according the The Independent, and is the grocer’s first dark store as it currently picks online orders in shops.

The 100,000sq ft store dwarfs Waitrose’s biggest physical store in the capital, the 70,000sq ft store in Canary Wharf, and signals a ramping up of the grocer’s online operations in the capital.

From this year, Waitrose is allowed to deliver within the M25 after a new deal was struck with Ocado. Ocado will continue to deliver Waitrose groceries too, but the pair will now go head to head in London. Waitrose last month relaunched its website in preparation for the roll out.

Waitrose boss Mark Price said he expects the grocer’s online sales to grow by between 40% and 60% a year.

The grocer will also offer its customers a wider selection of delivery slots which will run as late as 11pm.