A raft of top UK law firms have taken roles on Westfield's sale of a 50% stake in its shopping centre next to the site of the London 2012 Olympics, after the retail giant struck a £871.5m deal with two overseas pension funds.

Westfield has instructed three law firms on the deal, which will see the Australian property developer sell off 50% of Westfield Stratford City to Holland's APG and the Canadian Pension Plan Investment Board.

SJ Berwin is advising on the corporate aspects of the transaction – which values the development at more than £1.7bn – fielding a team led by corporate partner Michael Goldberg.

Freshfields Bruckhaus Deringer is advising Westfield on tax aspects of the transaction with a team led by corporate partner Michael Goldberg.

Ashurst, meanwhile, is advising on retail aspects of the deal with a team led by real estate partners Hugh Lumby, Antony Burnett-Scott and Jamie Chapman.

Lumby commented: "This is a hugely exciting transaction which will have a profound effect on the East End of London. It is due for completion well before the 2012 Olympics."

Westfield – which also owns a huge shopping mall in London's Shepherd's Bush – said the deal meant it had made a profit of £150m on the development a year earlier than had been expected.

APG and Canada Pension Plan instructed Allen & Overy (A&O) to advise on the transaction, which will see each of the two acquirers take a 25% stake in the shopping centre. The magic circle firm fielded a team led by real estate partner Daniel McKimm.

The mall is already 75% let by a line-up of major retailers including John Lewis and Marks & Spencer.