UPDATE 1-RHJ wins Chinese backing to buy Deutsche's BHF unit

* Renews bid to buy BHF from Deutsche Bank

* Secures additional funding from outside investors

* BMW heir, Chinese investors part of renewed bid

* German regulator Bafin still needs to approve deal

FRANKFURT, Sept 20 (Reuters) - Buyout firm RHJ International has secured backing from investors including a Chinese conglomerate for its acquisition of Deutsche Bank's BHF-Bank unit, as it seeks to win over the German regulator who derailed two previous deals.

The 384 million euros ($501 million) cash offer by RHJ's London-based Kleinwort Benson unit is subject to potential price adjustments and has to be approved by the German markets regulator BaFin, Deutsche and RHJ said on Thursday.

RHJ and Deutsche Bank had agreed a deal in March but this was rejected by BaFin, citing concerns over RHJ's funding. The regulator also scotched Deutsche Bank's initial plan to sell BHF to LGT, owned by the royal family of the Alpine principality of Liechtenstein.

On Thursday, RHJ said it had secured additional backing from outside investors including China's Fosun Group, BMW heir Stefan Quandt and funds controlled by U.S. investor Timothy C. Collins and Blackrock Investment Management.

Belgium-based RHJ said that under the deal, these investors would back a capital increase at Kleinwort Benson, a wealth management unit which RHJ acquired from Commerzbank in 2009 for 225 million pounds ($353.2 million).

Fosun said its investment would help it secure a foothold in Europe.

Two people close to the agreement said the prospective buyer planned to maintain the BHF brand.

Deutsche Bank has been on the lookout for a buyer since it inherited BHF with its 1 billion euro purchase of Sal. Oppenheim in March 2010.