As part of a £1bn investment plan, Waitrose has chosen Cricklewood in north London as the location for its first supermarket in eight years.

The upmarket grocer will open the store on Thursday and another supermarket in Hale Barns, Greater Manchester, next month. It also plans four smaller stores next year, including a supermarket in Oakham, Rutland, and three convenience stores in Bedminster (Bristol), Chalk Farm (London) and Springstead Village (Cambridge).

In 2024, Waitrose, which has more than 300 supermarkets, said it planned to open up to four large supermarkets and 100 convenience stores over five years and would also refurbish a number of outlets introducing meat, fish and sushi counters, on-site bakeries and fine wine sections.

Tina Mitchell, the retail director at Waitrose, said: “Our supermarkets provide the ultimate showcase for everything that sets Waitrose apart – from our unmatched quality and industry-leading welfare standards to the expert service of our partners.”

This year the company – led since January by the former Tesco executive Tom Denyard – also plans to refurbish 29 stores.

After a difficult period, when sales were hit by IT problems which led to gaps on shelves, Waitrose is holding market share, according to the latest figures from market analysts Worldpanel by Numerator. However, the chain is coming under pressure from Marks & Spencer, which now has a higher share of the grocery market, under some measures, after opening a number of new food-led outlets.

Sales at Waitrose rose 4% in the six months to 1 August. However, its underlying operating profit slid by £7m to £103m as it invested in keeping prices down and improving its loyalty scheme. It was also hit by higher energy costs during the summer heat wave.

Waitrose’s parent company, the John Lewis Partnership – which is owned by its staff – reported a £98m pre-tax loss in the half-year to 1 August, as sales fell at the department stores despite heavy investment in updating the outlets.

The company has been reducing the number of staff it employs directly as it tries to trim costs.

On Wednesday, the partnership announced it had signed its first company-wide union recognition deal. The collective agreement with Usdaw, the shopworkers’ union, comes ahead of new rights of union access in workplaces that come into force at the end of this month.

Joanne Thomas, the general secretary of Usdaw, said: “Usdaw already has members working within the business and this agreement will strengthen that presence and help us in supporting and representing members across the partnership. We now look forward to growing our membership and influence within the partnership and to working with the partnership’s management on finalising the details of how the agreement will work in practice.”