YouTube investors and executives including co-founders Chad Hurley and Steve Chen registered to sell 3.23 million shares, Mountain View, California-based Google said Thursday in a filing with the U.S. Securities and Exchange Commission.

Google bought San Bruno, California-based YouTube for US$1.65 billion in November to tap the market for online video advertising. Hurley and Chen, who founded YouTube in February 2005, may each sell shares worth about US$326.2 million as of Thursday's closing price. Sequoia Capital, YouTube's largest investor, may sell shares worth US$504.4 million.

"You can't overlook the fact that these guys had a great idea," said Allen Weiner, an analyst at Gartner Inc., a market research firm in Stamford, Connecticut. "Some of it was timing, but I think it impacted so many big businesses, which is what drove this price."

Shares of Google, owner of the world's most-used Internet search engine, declined US$1.47 to US$470.01 at 4 p.m. New York time in Nasdaq Stock Market composite trading. They have gained 2.1 percent this year.

YouTube is the most popular video-sharing site on the Internet, attracting more than 38 million U.S. visitors in December, according to Nielsen//NetRatings, which tracks Web use. Google's own video site had more than 20 million visitors.

YouTube has sparked criticism from some content providers because of copyrighted material uploaded by users. Last week, Viacom Inc. asked YouTube to remove 100,000 videos it said were posted without permission.

The Google filing Thursday highlights the range of investors who stand to benefit from the purchase of YouTube. Artis Capital Management LLC, a hedge fund, may sell Google stock worth about US$83 million. Brown University, Dartmouth College, the Ford Foundation, J. Paul Getty Trust and Oxford University Fund L.P. are among more than 100 investors that will benefit through Sequoia Capital's investment.

"The fact that an acquisition of such a young company took place at such a large scale does say something about the speed with which business is moving in Silicon Valley," said Sean Randolph, president of the Bay Area Economic Forum, a San Francisco-based group the promotes economic development.

YouTube employees will need to wait until their shares are vested, or eligible for sale, before cashing out. Google said it will pay registration fees for the shares, which will cost about US$333,337.

Google said investors' holdings include shares held under escrow, a provision that was part of the YouTube acquisition to protect against copyright claims.

Jawed Karim, who founded the company along with Hurley, 29, and Chen, 28, registered to sell 137,443 shares, worth about US$64.6 million. The purchase of YouTube was Google's biggest acquisition ever.

Other Internet startups in Silicon Valley may not see that same kind of payday, Weiner said.