SJ Berwin has landed one of its biggest instructions from Marks & Spencer (M&S) as the department store signs up to Portsmouth's £500m new shopping centre.

Real estate partner William Boss and associate Mark Mallon took the lead for M&S, which has signed up to 130,000 sq ft of space as the second anchor store in Portsmouth's Northern Quarter.

The new project is being developed by Centros Miller and will provide 80 new shops in Portsmouth's town centre. Centros signed a contract with John Lewis, the other anchor store in the development, in 2004, with planning consent granted in February this year. The site, which is scheduled to be completed in 2011, will also have 200 residential apartments and a four star hotel.

While Slaughter and May is the lead corporate counsel to M&S, the retail store also instructs Allen & Overy, Wragge & Co, Osborne Clarke and SJ Berwin, particularly on its real estate work.

The deal underlines a busy period for SJ Berwin's property department which in recent months has advised on deals including Royal Bank of Scotland's £1bn sale of Citi's London headquarters, Hilton Hotel Group's £51.7m sale of Edinburgh hotel The Caledonian and Delancey's £26.75m sale of 7 Moorgate in the City.

On this deal, CMS Cameron McKenna is advising Centros on all aspects of the development, led by real estate partner Mark Heighton. In the past Centros has used firms such as Macfarlanes.

Centros Miller is one of the UK's leading urban regeneration and mixed-use development companies and has a current development programme valued as more than £800m, covering the regeneration of more than 2,250,000 sq ft of space in UK town and city centres.