* Had 1 billion euros of debt at end September
* More jobs need to be cut - CEO Asbeck
* Shares plunge more than 25 percent (Adds details, background, shares, analyst comment)
DUESSELDORF, Germany, Jan 25 SolarWorld , once Germany's largest solar company, could face lengthy and painful talks with creditors as it seeks to restructure its debt, the chief executive said.
"Talks could take weeks and months," Frank Asbeck, dubbed the "sun king" for his outgoing nature, said on Friday, adding the company needed to cut more jobs in addition to the 250 announced last year to save costs.
He was speaking after SolarWorld warned late on Thursday it would need to make a "serious adjustment" to its debt to remain a viable company.
At the end of September 2012, the company had long-term debt of 1.03 billion euros ($1.4 billion).
SolarWorld is the latest German solar manufacturer to announce debt restructuring, following former heavyweights Conergy and Q-Cells. The latter filed for insolvency last year after months of negotiations with creditors.
Cuts in subsidies for solar energy, fierce competition from cheaper Asian rivals and massive oversupply of components have crushed Germany's solar industry - once the world's biggest producer of solar cells that convert light into electricity.
"Significant uncertainties continue to dominate and are an existential threat to SolarWorld," LBBW analyst Erkan Aycicek said. Shares in the company fell more than 25 percent on Friday.
Bondholders holding securities worth 550 million euros ($735.57 million) in total and maturing in July 2016 and in January 2017 would be hit most in the restructuring, the company said.
Lenders carrying SolarWorld's assignable bank loans on its balance sheet would also likely be affected, it added.
Asbeck said the company's liquidity was 220-230 million euros, largely unchanged from the end of September.
The company, which posted a 230 million euros net loss for the first nine months of 2012, is scheduled to present full-year results on March 21. ($1 = 0.7477 euros) (Reporting by Anneli Palmen and Christoph Steitz; Editing by Erica Billingham)