The regeneration of a 400-staff factory earmarked for closure passed a major milestone today after a deal was struck to open a Sainsbury store at the site.

Sanofi pharmaceuticals in Rainham Road South, Dagenham, faces mass redundancies next year when its plant shuts because of flagging demand for it cancer drugs.

But the global drug manufacturer announced this morning it had secured an agreement with the high-street chain to open a large supermarket, which is anticipated to create 400 new jobs.

The deal will help to draw new investors to the factory at a time when Sanofi bosses forge ahead with plans to turn the 108-acre site into a new business park.

Jim Moretta, the Sanofi site leader for Dagenham, said: “Our agreement with Sainsbury marks an important milestone in the regeneration process and is a project that will generate hundreds of new jobs.

“Securing a contract for development of the retail plot at the front of the site now enables us to concentrate our efforts on attracting businesses to the rest of the location.”

The news came just days after the Post reported that Sanofi was working with a leading IT firm to turn part of the factory site into a mini Silicon Valley featuring one of Europe’s biggest information centres.

The 60,000 sq ft supermarket would have 500 parking spaces, a petrol station and would stretch over 10 acres.

Sanofi was granted an “outline planning permission” to build new facilities at the site, including a supermarket, last year but Sainsbury will still need to apply for full planning permission with the council before opening the store.

Harriet Houlihan, London development executive for Sainsbury, said: “We are looking forward to working with Sanofi to bring forward this exciting regeneration project.

“Our plans for a new food store in this location will provide a great service for our customers while providing new jobs and training opportunities in the local area.”