Fremont solar power startup Solyndra has canceled plans for a $300 million initial public offering of its stock.

Instead, Solyndra will borrow $175 million from existing investors, which will be given promissory notes that can be converted to stock.

"Given the ongoing uncertainties in the public capital markets, we elected to pursue alternative funding from our existing investor base," CEO Chris Gronet said in a statement late Thursday. "This funding allows us to address strong customer demand by maintaining our aggressive growth plans."

Solyndra, which received a $535 million federal loan last year to build a new solar panel factory in Fremont, had filed with the Securities and Exchange Commission for its IPO in December.

According to a post Friday on the VentureBeat blog, analysts had been concerned that Solyndra's debt load could scuttle its IPO hopes.

Solyndra is moving forward with construction of its "Fab 2" plant, which Gronet said is two months ahead of schedule, with production expected to begin by the end of the year.

"Fab 2 can't come on line a minute too soon," he said.

Contact Frank Russell at 408-920-5876. Follow him at Twitter.com/mercspike.