(Adds details, background)
MADRID, March 26 (Reuters) - Repsol Chairman Antonio Brufau is expected to hand over all executive powers to his number two Josu Jon Imaz in April, the Spanish oil group said on Thursday, as he takes a step back following a decade at the helm.
Repsol's board is expected to agree on April 30 that executive functions be handed to the chief executive, the firm said in a filing with the stock market regulator.
Even after naming Imaz as CEO last April, the group retained a structure in which Brufau oversaw control of finances and communication, though he had already started to hand over some executive powers.
Brufau has led Repsol through a turbulent period including the seizure of its YPF unit by Argentina in 2012 for instance.
Shares were little changed, trading at 17.440 euros at 1240 GMT versus a flat European energy sector index.
The company said earlier on Thursday it would ask shareholders to re-elect Brufau as chairman, in a non-executive capacity, at a meeting also due on April 30.
Imaz, a former Basque politician who holds a PhD in chemical science, was hired by Brufau in 2008 and promoted by him in 2014 to a new chief executive post. That put him in charge of day-to-day management at the company, although his boss kept control over strategy and finances.
Imaz steered one of Repsol's most recent major ventures, the $13 billion takeover of Canada's Talisman.
(Reporting by Jose Elias Rodriguez; Writing by Elisabeth O'Leary; Editing by David Holmes)