BERLIN (Reuters) - German Environment Minister Norbert Roettgen, who took the blame for a historic defeat for Chancellor Angela Merkel's conservatives in a regional election on Sunday, is to step down and be replaced by her parliamentary whip Peter Altmaier, official sources said on Wednesday.
Merkel was expected to make the announcement in a statement to the media scheduled for 4.30 pm (10.30 a.m. EDT). Roettgen, 46, was her protege, deputy chairman of her Christian Democrats (CDU), and once seen as a potential successor to the chancellor.
He quit his regional party post after taking responsibility for the CDU's worst ever election result in Germany's most populous state, North Rhine-Westphalia, on Sunday where he stood for state premier. The opposition Social Democrats (SPD) scored a resounding victory and retain power with their Green allies.
Altmaier is a loyal Merkel ally who has helped her keep conservative lawmakers on-side and push euro zone rescue legislation through parliament. Two sources in Berlin told Reuters he was set to replace Roettgen.
Roettgen's political star began waning last year when he had to defend Merkel's U-turn on nuclear power - she accelerated the closure of nuclear plants after Japan's Fukushima disaster - to business worried about its electricity bills in industrial areas like his political homeland, NRW.
The government's energy policies suffered another setback last week when proposed cuts in subsidies for Germany's solar power industry were suspended by the upper house of parliament (Bundesrat), where the federal states are represented.
States run by the SPD oppose slashing the solar feed-in tariffs, as do some conservative-run regions like Bavaria and parts of eastern Germany where the solar industry is a source of jobs and revenue.
(Reporting by Markus Wacket; Writing by Stephen Brown; Editing by Noah Barkin)