A raft of international law firms have advised on buyout house The Blackstone Group's £480m acquisition of the Chiswick Park office development in West London.

Simpson Thacher & Bartlett and City firm Herbert Smith were jointly instructed by Blackstone on the deal, with SJ Berwin and Ashurst advising the seller, Chiswick Park Unit Trust.

Simpson Thacher took the main corporate real estate role on the deal, fielding a team led by US-qualified London-based real estate private equity partner Farhad Karim and finance partner Stephen Short. Herbert Smith's team, providing UK real estate advice, was led by real estate head Ian Cox.

Real estate partner David Ryland led the SJ Berwin team advising the seller, while Ashurst's team for Chiswick Park Unit Trust included real estate partner Anthony Burnett-Scott, construction partner Ann Minogue and associates Henry Moss and Adriano Amorese.

Deutsche Bank, which is providing a £300m loan backing the acquisition, instructed magic circle firm Clifford Chance, where finance partner Jane Sing took the lead. Freshfields Bruckhaus Deringer banking partner Jeffrey Rubinoff advised Singapore sovereign wealth-fund GIC on a £60m junior loan.

Simpson Thacher's Karim commented: "The deal was a highly collaborative project among all the law firms involved, and completing another real estate transaction for Blackstone is very rewarding indeed."

A number of offshore firms also played a role providing Jersey advice on the deal, including Appleby, Carey Olsen, Mourant Ozannes and Ogier.

The 1.9 million sq ft business park, which houses companies such as Discovery Channel and Singapore Airlines, was initially put up for sale in 2009.