LOS ANGELES -- Facebook's long-awaited IPO filing lifted shares of freshly minted public Internet companies, including recent laggards Zynga and Groupon.
Zynga Inc.'s business is closely tied to Facebook, because many of its addicting games such as CityVille and Mafia Wars are played on the social-networking site. Facebook's initial public offering filing revealed that 12 percent of its fast-growing revenue comes from Zynga.
"It shows (Zynga's) an important partner, they're going to participate in Facebook's growth," said Wedbush analyst Michael Pachter.
Zynga shares jumped $2.01, or 19 percent, to $12.61 in midday trading Thursday.
Daily deals site Groupon Inc. shares rose 6.9 percent to $22.97, while jobs networking site LinkedIn Corp. shares rose 5.9 percent to $76.62, even though their revenues aren't tied to Facebook.
Online radio service Pandora Media Inc. shares rose 2.6 percent to $13.23 and American depositary shares of Chinese social networking company Renren Inc. jumped 50 cents, or 10 percent, to $5.51.
All five companies made their stock market debuts last year. Only LinkedIn's shares have traded consistently above their IPO price.