* Korthout had been CFO at Robeco since 2002
* Takes over financial role from CEO Deckers (Adds details, background)
AMSTERDAM, Aug 24 (Reuters) - Dutch private bank Van Lanschot on Tuesday named Constant Korthout as its new chief financial and risk officer, splitting off some of the duties held by Chief Executive Floris Deckers.
Korthout, 47, joins Van Lanschot from Robeco, the asset management arm of Dutch bank Rabobank, which has 145 billion euros ($184.4 billion) in assets under management. He had been Robeco's CFO since 2002.
Van Lanschot said the new addition would expand its management board to four members and will be discussed at an extraordinary meeting of shareholders to be held as soon as possible.
The bank, which dates to 1737, did not have a traditional CFO on the board until now. Instead, the major risk and financial control functions fell within CEO Deckers' portfolio.
Korthout is the second top executive to leave Robeco in the last six months. In February, board member Sander van Eijkern resigned in a difference of opinion on strategy with new CEO Roderick Munsters. (Reporting by Ben Berkowitz; Editing by Erica Billingham)