Thomas Nielsen has stepped down after just eight months as CEO of RealNetworks, the Seattle-based company best known for its RealPlayer multimedia-streaming software.
Rob Glaser, the company's founder and chairman, has returned to the CEO job to fill in on an interim basis, RealNetworks said.
Nielsen is not leaving to take a position elsewhere, the company said in a statement Tuesday.
RealNetworks has struggled financially in recent months. The company lost $17 million in the first quarter of 2012, following a loss for the full year in 2011. In January, it sold $120 million in video software and patents to chip maker Intel.
"I come back to RealNetworks with a sense of great urgency to set the company on a long-term path to success," Glaser said in the statement.
Glaser founded RealNetworks in 1994. Prior to that he had been vice president of multimedia and consumer systems at Microsoft.