NEW YORK ( TheStreet) -- Facebook ( FB) shares slipped in pre-market trading today as the social networking phenomenon prepared for its first full day as a public company. The Menlo Park, Calif.-based firm made an eagerly anticipated and eventful public debut on Friday in the biggest-ever tech IPO. After pricing its offering at $38 a share, Facebook opened at $42.05 and briefly jumped to a high of $45 before closing at $38.23.
Even though the widely anticipated first-day pop failed to materialize, Facebook's IPO still saw the Nasdaq Exchange struggle with unusually heavy volume. The exchange resorted to manually delivering executions to brokerage houses. On Sunday, Robert Greifeld, the CEO of Nasdaq OMX Group Inc. ( NDAQ), acknowledged technology problems related to Facebook's listing, according to a published media report, saying the exchange was "humbly embarrassed" by Friday's events. Shares of Facebook dipped 3.3% to $36.96 in pre-market trading today. Nasdaq shares fell 2.5% to $21.45. Online gaming specialist and key Facebook partner Zynga ( ZNGA) also fell before the market open. Shares of the Farmville maker slid 4.1% to $6.87 on the Nasdaq. Yahoo! ( YHOO) shares climbed 5.7% to $16.30 before the market open after the Internet giant reached a deal to sell up to half its stake in Alibaba back to the Chinese e-commerce company. The two companies announced the $1.7 billion deal late Sunday. "Today's agreement provides clarity for our shareholders on a substantial component of Yahoo!'s value and reaffirms the significance of our relationship with Alibaba," said Ross Levinsohn, the interim CEO of Yahoo!, in a statement released on Sunday. "We look forward to continued collaboration with the Alibaba team on business initiatives as we explore joint opportunities for growth and benefit from Alibaba's future." The Sunnyvale, Calif.-based Internet company was also one of the most active Nasdaq stocks in pre-market trading on share volume of 1,060,246. Hard-drive specialist Western Digital ( WDC), which announced plans to move its listing to the Nasdaq, was up 1.2% to $35.06 today. --Written by James Rogers in New York. >To follow the writer on Twitter, go to http://twitter.com/jamesjrogers. >To submit a news tip, send an email to: firstname.lastname@example.org. Check out our new tech blog, Tech Trends. Follow TheStreet Tech on your wireless devices.