UPDATE 1-Opel to stick to business plan despite new CEO

* Stracke steps down but his plans remain in place -Opel

* Plans foresee half of investments earmarked for Germany

* Analysts expected restructuring plans would be revised

FRANKFURT, July 13 (Reuters) - Ailing European carmaker Opel said it would not need to draw up a new mid-term business plan following a decision by parent General Motors Co to abruptly replace its chief executive and appoint GM Vice Chairman Stephen Girsky as interim CEO.

"This shift in leadership does nothing to change Opel's commitment to its revitalization plan. Opel is a cornerstone of GM's global operations and GM fully supports the current plan to strengthen Opel and improve its operational competitiveness," a spokesman for Opel said on Friday.

Since GM emerged from bankruptcy three years ago, Opel - known in Britain as Vauxhall - has racked up a total of $3.5 billion in operating losses thanks to an ever-shrinking European car market and a bloated fixed-cost base.

Auto industry analysts had warned that GM's obvious impatience with the pace of Opel's restructuring meant Girsky would be more inclined to take harder measures to reduce losses.

The departure of Karl-Friedrich Stracke comes only weeks after progress had finally been achieved in laying the foundations for a turnaround.

German unions agreed to enter negotiations with Opel on the basis that an agreement would involve no compulsory layoffs through 2016, in exchange for wage concessions and approval to end production at the Bochum, Germany plant.

The European arm of GM had also recently said roughly half of its investments through 2016 would be made in Germany, indicating the company does not plan to eliminate staff there.

Roughly half of Opel's workforce is employed in Germany.

Opel had also held out the possibility of manufacturing Chevrolets in Opel's European manufacturing plants to better improve profitability and safeguard jobs.

Analysts have also argued that PSA Peugeot Citroen's move to cut 8,000 jobs and shutter its Aulnay factory in 2014 may encourage rival automakers to deepen or bring forward their own capacity reduction plans.