Google’s total capital investment in data centers and IT infrastructure was about US$3.44bn in 2011, according to the company’s quarterly earnings statements for the year.

Google invested $951m in IT infrastructure, including data centers, servers and networking equipment, in the fourth quarter. This investment was $890m in Q1, $917m in Q2 and $680m in Q3.

The company’s cost of revenue, comprised primarily of the cost of data center operations, content acquisition and other costs, went up to $1.25bn in the fourth quarter, compared to $877m in the fourth quarter of 2010.

Google reported net income of about US$9.74bn on about $37.9bn in revenue for the full year. For the year’s fourth quarter, Google’s income was about $2.7bn on about $10.6bn in revenue.

Thus, Google spent about 12% of its revenue on data center operations in the last three months of 2011. This is compared to 10% of revenue during the same period one year before.

Commenting on the results, Google CEO and one of its founders Larry Page said this was the first time the company’s quarterly revenue passed the $10bn mark.

“I am super excited about the growth of Android, Gmail and Google+, which now has 90m users globally – well over double what I announced just three months ago,” he added.