The retailer, which opened its 400th store last month, said it was on track to open at least a net 50 stores by the end of the financial year, creating 2,500 UK jobs.
It is in talks with at least six retailers on right-sizing their estates, chief executive Simon Arora said, without naming who they were.
Several retailers and supermarkets have been shedding stores as leases come up for renewal as consumers spend less time and money in big stores and more time online.
Homebase parent company Home Retail Group announced plans last month to close a quarter of its estate while DIY group Kingfisher has also been seeking to partner with retailers on some of its over-spaced stores.
Goldman Sachs analysts released a note on Monday, warning that supermarkets need to cut 20 per cent of space in their larger stores to return to growth and stem slowing sales.
B&M, which listed on Aim in June, posted a 34 per cent rise in earnings to £73m in the first half to 27 September.
Group revenues, including its newly acquired German business Jawoll, jumped by 29 per cent to £739.8m while UK like-for-like sales were up 4.8 per cent.