The deal is expected to close by late April. Google declined to disclose any financial terms.
According to a statement released by Google, the company intends to make Urchin's software available to advertising clients, in order to help them increase the return on investment and make their Web sites more effective.
A Google spokesman declined to comment on the possible pricing structure for Urchin's technology, but speculation abounded on search-watching sites Tuesday that Google may offer the Web analytics tools for free, or for a very low price. Such a move could crowd out search engine marketers who search medium and small businesses.
Google's move to acquire Web analytics technology comes more than two years after competitor Yahoo! purchased Carlsbad, Calif.-based Keylime Software for about $9.5 million in cash. Keylime also specializes in Web analytics.