Online search leader Google delivered on high expectations today, posting solid quarterly results and signaling confidence in the year ahead, while spiting nagging concerns about economic conditions or sagging ad sales rates.

The company reported first-quarter 2008 revenues of $5.19 billion -- a staggering 42 percent greater than Google's (NASDAQ: GOOG) revenue a year earlier, and even 7 percent higher than its fourth-quarter 2007 revenue.

Net income topped $1.31 billion, or $4.12 per share -- up slightly from last quarter's $1.21 billion, or $3.79 per share.

Minus one-time charges due to taxes, stock-based compensation and other write-downs, net income would have totaled $1.54 billion, or $4.84 per share. Analysts had pegged the firm for earnings of $4.52 per share, according to Thomson Financial.

On the same basis, Google posted per-share earnings of $4.43 in Q4 2007.

Industry watchers had been worried that the economic condition would prompt companies to slash marketing budgets, damaging Google's advertising revenue. Those worries seemed to be confirmed earlier this year, when Google reported lower-than-expected earnings, and further reinforced when a number of reports pointed to flat growth in the online powerhouse's ad sales.

The results included a small impact from Google's acquisition of DoubleClick, which concluded in mid-March. The company said DoubleClick's impact on its results was only "slightly dilutive" to operating income, net income and earnings per share.

"Our ongoing innovation in search, ads, and apps helped drive healthy growth globally across our product lines, yielding another strong quarter for Google," CEO Eric Schmidt, said in a statement. "As we integrate DoubleClick into our advertising platform, we see exciting new ways to improve the user experience and increase value for our advertisers and partners. Also, while exercising operational discipline, we continue to explore opportunities that add value to users everywhere and to Google in the long term."

Also not included in Google's income accounting were traffic acquisition costs, or TAC -- costs associated with reimbursing partners like Web site publishers that host its ads. The company said it spent $1.49 billion in TAC during the quarter.

Google's rosy quarterly performance also comes as it's becoming more closely involved in Microsoft's attempts to acquire Yahoo, a rival to both companies in search and online media.

Seemingly in a move to defy Microsoft's (NASDAQ: MSFT) aggressive overtures toward Yahoo (NASDAQ: YHOO), it joined Google recently in working together, with Yahoo taking AdSense out for a test drive.

Still, as would a Yahoo acquisition by Microsoft, an alliance between Yahoo and Google would be closely scrutinized by antitrust regulators, legal experts have said.