FRANKFURT: German engineering services firm Bilfinger plans to sell the power-plant unit blamed for six profit warnings as a first step in what could be a more drastic restructuring, its chief executive said two weeks after taking over.

Germany's policy switch towards renewable energy has caused upheaval in its power market and hurt Bilfinger's utility clients, squeezing the company and exposing internal failings.

Bilfinger said a further writedown of the unit, which accounted for about a fifth of Bilfinger's output in 2014 and which services the nuclear and fossil fuel plants threatened in the push for renewables, would push it to a "significant" net loss for the first half and possibly a full-year loss.

Shares in Bilfinger plunged more than 16 percent to a six-year low on Thursday as investors wondered whether worse was to come and feared the company would stop paying a dividend.

Bilfinger, which in its heyday built the Sydney Opera House and the Munich Olympic Stadium, has lost two-thirds of its value since April last year and is now worth about 1.7 billion euros

($1.9 billion).

Former Swissport CEO Per Utnegaard only arrived on June 1, brought on board by new Chairman Eckhard Cordes, an ex-Daimler and Metro executive installed by European activist investment firm Cevian, which owns 26 percent of Bilfinger.

Asked if he had acted too quickly, he said: "If I look at the results of Power in the last three or four years, I would rather ask why the strategy did not change earlier."

Former CEO and ex-Hesse state premier Roland Koch quit last August after Bilfinger's second profit warning.

Some shareholders blame Koch for the company's problems, saying he was wrong to sell the traditional construction business that could have helped balance out the more volatile, project-based services business on which he chose to focus.

The move, however, was started under his predecessor and later interim CEO, Herbert Bodner.

DZ Bank analyst Jasko Terzic wrote in a note: "We do believe that this quick decision indicates that the business environment remains weak and that the project management (execution, risk controlling) suffers from severe problems."

"This should result in another high loss bottom-line and put the dividend at risk, in our view," said Terzic, keeping his "sell" rating on the stock.

Power made adjusted earnings before interest, tax and amortization (EBITA) of just 8 million euros ($9 million) on output of 1.45 billion last year as German utility customers slashed spending.