After Google Inc.’s second-quarter results missed Wall Street estimates, the search engine giant’s shares slipped Friday even though net income and revenue climbed sharply.

Results were hurt as Google hired aggressively to maintain its commanding lead in online search and expand into other businesses. The company is pushing into everything from Web display advertising and mobile ads to operating systems for computers and wireless devices, although Google still makes much of its money by serving up advertising alongside Internet search results.

Google said it added nearly 1,200 employees with more than 21,800 workers. The company indicated that it will continue to hire at an aggressive pace.

In a research note, “Google is escalating its investments as it transitions from being a ‘one-trick pony’ to generating material revenues from non-search segments.”

Google reported earnings of $1.84 billion for the second quarter, or $5.71 per share, on $6.82 billion in revenue. It posted an income of $1.48 billion in the same quarter of 2009, or $4.66 per share, on $5.52 billion in revenue.

(Thanks to Bloomberg Businessweek and Wikipedia)