Google Inc's fourth-quarter revenue grew 17 percent, beating Wall Street expectations, as advertisers and Web surfers turned to the Internet search engine during the holiday shopping season.

But Google's revenue came in at the low end of the whisper numbers expected by some investors, and its shares fell about 5 percent to $552.52 in after-hours trade on Thursday.

Google posted net income of $1.97 billion, or $6.13 a share, in the three months ended December 31, compared with $382.4 million, or $1.21 a share, in the year-earlier period when the company took a roughly $1 billion impairment charge to account for its investments in AOL Inc and wireless service provider Clearwire Corp.

Excluding certain items, Google reported EPS of $6.79, compared with the $6.48 expected by analysts on average, according to Thomson Reuters I/B/E/S.

Revenue at Google, the world's No. 1 search engine, totaled $6.67 billion, compared with $5.7 billion in the fourth quarter of 2008.

Google's revenue, excluding the traffic acquisition costs it paid to partners, was $4.95 billion, above analysts' average expectation of $4.92 billion.

(Reporting by Alexei Oreskovic; Editing by Richard Chang)