Norton Rose has advised SG Hambros – part of Societe Generale's (SocGen's) private banking unit – on its eye-catching acquisition of ABN Amro's E1bn (£699m) London-based private banking business.

The top 10 City law firm acted opposite magic circle giant Freshfields Bruckhaus Deringer on the private buy-out, which was for an undisclosed sum. The business is known to have at least E1bn of assets under management. Norton Rose, which is also on SocGen's global panel, was handed the mandate six weeks ago.

The firm fielded a team led by corporate partner Richard Sheen, including corporate partner Philip Mellor, regulatory partner Jonathan Herbst, employment partner Paul Griffin, real estate partner Wasim Khan and tax partner John Challoner.

Sheen pointed to the firm's history with the client, saying: "We do a lot of work with the SocGen group and have good historical relations with SG Hambros Bank."

Freshfields, meanwhile, acted for longstanding client ABN Amro, with corporate partner Vanessa Knapp and associate Sam Newhouse taking the headline roles.

The deal, which will close in November, comes as ABN Amro continues to find itself subject to a bidding war between a Royal Bank of Scotland-led consortium and Barclays. Dutch giant NautaDutilh and Allen & Overy are advising ABN Amro on the deal.

Elsewhere, in another deal affecting the bank, elite Manhattan firms Wachtell Lipton Rosen & Katz and Davis Polk & Wardwell have also won plum roles on Bank of America's $21bn (£10.4bn) acquisition of ABN Amro subsidiary LaSalle Bank.