Northampton-based Travis Perkins is to close 30 branches of its builders merchant business
The move will put at risk the jobs of about 600 people, who the have been told of the news.
The firm, which employs 28,000 people across its 2,060 stores, said it feared an "uncertain UK outlook" over the next 12 month.
Low sales in its heating and plumbing division led to lower profits than managers had been expecting.
Branches of Travis Perkins, Benchmarx, BSS and PTS will close but DIY store Wickes is no affected.
John Carter, Travis Perkins chief executive, said it was still too early to predict customer demand in 2017 with certainty.
He said: "Given this uncertainty, we will be closing over 30 branches and making further efficiency driven changes in the supply chain."
The job losses will result i 'exceptional charges' of between £40m and £50m , although the firm claims the cash cost is expected to be recovered by the overall money saved within 18 months.
The company is also closing 10 smaller distribution centres and writing off IT equipment.
Shares in the company fell five per cent in early trading on Wednesday.