BERLIN (Reuters) - Wintershall Dea said on Wednesday that the current management board will step down after the transfer of its non-Russian oil and gas assets to Britain's Harbour Energy.

CEO Mario Mehren, COO Dawn Summers and CFO Paul Smith will remain members of the management board until the transaction closes and will then resign from their mandates, it said.

Stefan Schnell, currently senior vice president of Group Reporting & Performance Management at BASF, will be proposed as chairperson (CEO) of Wintershall Dea as of the closing of the transaction, expected in the fourth quarter.

Larissa Janz, vice president of special projects at Wintershall, would then assume the role of deputy CEO.

Harbour Energy agreed in December to acquire Wintershall Dea's non-Russian oil and gas assets in a $11.2 billion share and cash deal with co-owners BASF and LetterOne that creates one of the world's biggest independent producers.

(Writing by Miranda Murray, Editing by Rachel More)