Internet advertising giant Google announced this week that it would cut 25 percent of the US-based staff at recently-acquired DoubleClick, or about 300 employees. Google also announced that it would sell DoubleClick's search engine marketing unit in order to maintain editorial independence.

"Since our acquisition of DoubleClick closed on March 11, we have been working to match and align DoubleClick employees in the US with our organizational plan for the business," a Google statement reads. "As with many mergers, this review has resulted in a reduction in headcount at the acquired company."

DoubleClick currently has 1200 employees in the US and other 300 overseas, and Google has reserved the right to reexamine those international employees at a later date. While Google was widely expected to cut jobs at DoubleClick--thanks mostly to a blog post last month by Google CEO Eric Schmidt--the cuts were deeper than expected.

Google paid $3.1 billion for DoubleClick, a purchase that was widely challenged by competitors, including Microsoft. Antitrust regulators in the US and Europe examined the merger but found no cause for contesting it.