* Says investment partner may have falsely pledged German bonds
* Raises worries Suntech may need to seek new financing
* Shares fall 15 percent to all-time lows
HONG KONG, July 30 (Reuters) - Suntech Power Holdings Co Ltd said on Monday that its partner in a solar development fund might have defrauded it with a bogus collateral pledge of hundreds of millions of euros of German bonds, sending its shares to all-time lows.
"We now suspect that the German government bonds may not have existed and Suntech may have been a victim of fraud," Chief Executive Officer Zhengrong Shi said on a conference call.
Shares of China-based Suntech shares fell more than 15 percent to $1.33 on the New York Stock Exchange as investors feared the world's largest maker of solar panels would have try to tap debt markets to raise more than $500 million to refinance a bond obligation due next year.
"They're going to need an additional infusion from somewhere," said Ardour Capital Investments analyst Adam Krop.
That financing fear comes as solar companies around the globe struggle to survive a drop of more than 60 percent in panel prices since the beginning of 2011 that has virtually erased profits in the industry.
In the conference call on Monday, Suntech executives said the company was looking into securing a new credit facility or issuing bonds in China to raise the money to cover a $541 million convertible bond that comes due in 2013.
Suntech currently has about $3.5 billion in total liabilities, according to ThomsonOne data.
The steep drop in panel prices stemming from a glut of production capacity of the renewable energy systems has forced several solar makers in the United States, Europe and China to shutter their operations, and analysts expect more to follow in the coming months.
Suntech said it might delay the release of its second-quarter results, but would provide some operating data later this month.
In a statement issued early on Monday, Suntech said that as part of its due diligence to sell the Global Solar Fund, its lawyers discovered that 560 million euros ($692.72 million) worth of German government bonds pledged to the company by asset management firm GSF Capital Pte may never have existed.
Suntech owns 80 percent the Global Solar Fund, while CEO Shi owns 10 percent. GSF Capital, which is run by Javier Romero, owns the remaining 10 percent.
GSF Capital could not be reached for comment.
Suntech said there was no indication that its management had any involvement potential fraud, and that documents related to the collateral appear to have been fabricated.
Wall Street analysts have long criticized Suntech's disclosures around GSF, which owns 145 megawatts of solar projects in Italy.