Duff & Phelps, the US financial advisory and investment banking firm, has been acquired by a consortium led by Abu Dhabi-backed asset management firm Carlyle Group in an all-cash transaction valued at around $665.5m (£430m).

Other members of the buying group include Stone Point Capita, Pictet & Cie, on behalf of certain of its clients, and funds managed by Edmond de Rothschild Group.

The deal was first put on the table at the end of last year, and included a 'go shop' clause which gave Duff & Phelps a period in which to seek an alternative buyer. No other potential investor came forward, so the consortium's bid has now gone ahead. Duff & Phelps' shares will no longer be listed on the New York Stock Exchange.

Noah Gottdiener, CEO of Duff & Phelps, said the transaction 'is in the best interest of our stockholders, who will receive an immediate and certain cash premium for their shares. Importantly, the transaction will be structured to preserve the firm's independence as we serve our clients in the future.'

Olivier Sarkozy, MD and head of Carlyle's global financial services group, said regulatory demands, implementation of new accounting policies and requirements for increased corporate disclosure and third party validation were likely to offer 'significant' growth opportunities for Duff & Phelps core products and services.

'We will harness Carlyle's and Stone Point's global networks while leveraging Duff & Phelps preeminent brand to foster growth in new geographies. Additionally, we believe the involvement of Pictet and Edmond de Rothschild Group will support the company's initiatives to enhance its international presence and expand its limited partner client base,' Sarkozy said.