UPDATE 1-German solar group Conergy says to file for insolvency
* Says investor could help keep operations going
* Shares indicated down 1.4 percent in pre-market trade
(Adds details on sector, background on possible investor)
FRANKFURT, July 5 (Reuters) - German solar group Conergy said it would file for insolvency on Friday, the latest casualty in an industry battered by overcapacity and plunging prices.
Sources close to the matter told Reuters on Monday that Conergy was close to striking deal that would see an Asian investor take a substantial stake in the firm.
Conergy said on Friday it remained confident of "achieving a continuation of the whole business operations in the context of insolvency proceedings by means of an investor".
The solar industry is grappling with fierce Asian competition, falling government subsidies for solar energy and oversupply - a deadly combination that has already undermined large players such as U.S.-based Solyndra as well as Q-Cells and Solon in Germany.
Western solar players have long claimed their Chinese peers are selling their products below production costs, culminating in an acrimonious trade dispute between Europe and China.
Conergy, once Europe's largest solar group, had sales of 473.5 million euros ($611 million) last year and an operating loss of 83 million. During the peak of the solar boom in 2007, Conergy's market capitalisation was more than 2.2 billion euros. It now stands at 57 million euros.
($1 = 0.7744 euros)
(Reporting by Christoph Steitz; Editing by Victoria Bryan and Mark Potter)