The sale to RHJ, the Brussels-listed investment group that failed in its bid to buy GM's European car unit Opel last month, is expected to close in the first quarter of 2010, subject to approval by regulators.

"RHJI plans to adopt Kleinwort Benson as an overarching brand for its financial services businesses going forward," RHJI Chief Executive Leonhard Fischer, a former Dresdner Bank executive, said in a statement.

Kleinwort Benson, a unit of Dresdner Bank that Commerzbank bought this year, specialises in wealth management in Britain.

The European Commission had demanded the sale of Kleinwort Benson as a condition for approving aid to Commerzbank from German bank rescue fund Soffin.

Soffin has granted 18.2 billion euros (16.7 billion pounds) worth of assistance to the lender, which was hit by the financial crisis and its takeover of Dresdner Bank.

Commerzbank said its investment banking business remained unaffected by the transaction.

Commerzbank has also sold wealth management operations in Belgium and Switzerland.

(Reporting by Jonathan Gould and Chris Wickham, Editing by Michael Shields)