Dec. 12 (Bloomberg) — HelioVolt Corp., a closely held thin-film solar panel maker, received about $12.2 million to expand production.

The financing was provided “mainly” by existing investors including New Enterprise Associates Inc. and SK Innovation Co., Rick Yang, an NEA senior associate, said today by telephone. HelioVolt, based in Austin, Texas, began commercial manufacturing in 2008, and the funding will be used to increase production and develop new products, he said.

“The existing investors in the company are seeing a lot of good things happening, and we want to continue the momentum and capitalize on that,” Yang said.

SK, South Korea’s biggest refiner invested $50 million in the company’s $85 million Series C financing round last year.

HelioVolt disclosed today’s investment in a filing. Chief Financial Officer Steve Darnell didn’t return a phone message seeking comment.

To contact the reporter on this story: Andrew Herndon in San Francisco at aherndon2@bloomberg.net

To contact the editor responsible for this story: Reed Landberg at landberg@bloomberg.net