Shares of Facebook (Nasdaq: FB), the No. 1 social networking site, vaulted nearly 9 percent in  Wednesday trading following CEO Mark Zuckerberg's acknowledgement of his company's "disappointing" performance since its highly touted May 17 initial public offering.

Facebook shares rose as high as $21.16 before closing at $20.91, up $1.48, or 7.6 percent, trimming the loss in post-IPO activity to only 46 percent.

Zuckerberg, 28, spoke in San Francisco on Tuesday at the TechCrunch Disrupt conference. Techcrunch is a unit of AOL Inc. (NYSE: AOL). He  said Facebook was concentrating heavily on developing apps for the mobile sector and was looking forward to new technical ties to Apple (Nasdaq: AAPL), the world's most valuable technology company.

"We care about our shareholders" Zuckerberg said. He added that the Menlo Park, Calif.-based company was building "a mission and building a business." He said the company would improve its search function and likely wouldn't develop a smartphone. He also urged customers and investors to judge Facebook's performance, not stock price.

TechCrunch posted video of the Facebook CEO's remarks on its website.

To contact the editor, e-mail: