Shares of Google Inc. (GOOG) fell as much as 6.5 percent on Tuesday, as selling restrictions were lifted on 39 million shares held by employees and early investors in the newly public Web search company.

The lockup expiration more than doubled the number of shares eligible for trade, to around one-fourth of total shares outstanding.

Industry analysts said the stock had been expected to slip somewhat on Tuesday as the selling restrictions were lifted but they said most investors were likely more interested in the long-term fundamentals of Google's business.

"It's really the underlying fundamentals of the company that are more important than the supply and demand characteristics of the stock," said David Garrity, an analyst at Caris & Co (search). "I think it's very encouraging that everyone has known that these IPO lockup expirations (search) were coming, yet we've seen the stock trade up meaningfully going into today."

Shares of Google, which had fallen as low as $165 just last week after jumping to a record high of $201 on Nov. 3, had risen steadily over the last three trading days. The stock debuted at $85 in mid-August and available shares had been scarce relative to other new IPOs, helping to fuel demand.

Garrity, who has a "buy" rating on the stock, said: "We would argue that investors should take advantage of the opportunity" of a sell-off to buy more shares.

Another analyst, Robert Becker of Argus Research Corp. (search) , noted that Tuesday's lockup expiration was part of a larger schedule to lift selling restrictions.

Nearly 227 million more shares are scheduled to become eligible for trade over the next three months. That figure includes almost 177 million shares that will become available for trade in mid-February, when the last IPO-related selling restrictions are lifted.

"More important factors driving the immediate share price will be investors' outlook for how Internet services companies are going to do in the fourth quarter and what the impact of Google's products will be over time," Becker said.

Google shares were down $11.25, or 6.1 percent, to $173.62 after falling as low as $172.81 during the session.