FRANKFURT - General Motors's turnaround plan for its European carmaker Opel will likely be completed only in January, GM Europe President Nick Reilly wrote in a blog posting on Thursday.

Although we had hoped to have the new business model finalised in December, it appears that more work needs to be done and further consultations will not be rushed, Reilly said.

This is going to be one of the largest, most complex industrial reorganisations in European manufacturing in years. It will affect thousands of people and their families (and) impact plants and other stakeholders.

Opel plans to cut around 8,300 jobs from its workforce of 50,000 in a 3.3 billion euro ($4.85 billion) overhaul that seeks state aid from countries with Opel plants including Germany, Britain, Spain and Poland.

Reilly, who also serves as chief executive of Opel and its British sister brand Vauxhall, was initially appointed to restructure the company on an interim basis.

Following last Tuesday's ouster of GM CEO Fritz Henderson, Reilly reiterated as recently as Dec. 2 that he intended to present a plan for the future of Opel by the middle of December.

Only two days later the U.S. carmaker said it was scrapping plans to find an external executive to run Opel and announced Reilly would stay on board after the Welshman accepted GM Chairman Ed Whitacre's request to take on the job full time.

Since then, GM management and labour leaders at Opel have resolved to work together to turn around the European operations after both sides showed a willingness to compromise on key issues, such as recognising union demands that investments in new product were a top priority as part of a long-term plan.

Our company needs great products and a winning product portfolio, which includes future technologies and investments. To that end, I held a day-long meeting with senior Opel leadership Tuesday to strategise on what needs be done now and in the new year, Reilly said on Thursday in the blog:

here (Reporting by Christiaan Hetzner, Editing by Michael Shields)