Google has today started laying off DoubleClick staff, less than a month after its acquisition of the advertising company was given the green light by EU authorities.

Just a day after the buy-out, Google warned that there would be cuts and today has confirmed that 300 jobs are to go.

The redundancies equate to 25% of DoubleClick's US workforce.

Google's chief executive Eric Schmidt has imnplied that there may also be some cuts in the future for Google's "overseas operations", namely the 300 people who work outside of the US.

In a statement, Google said: "Since our acquisition of DoubleClick closed on 11 March, we have been working to match and align DoubleClick employees in the US with our organisational plan for the business".

"As with many mergers, this review has resulted in a reduction in head-count at the acquired company."

The BBC reports that some staff have gone already while others will be offered transitional roles or temporary contracts which will be terminated after the two companies are fully merged.

In separate news, Google has revealed its plan to sell off a DoubleClick operation called Performics Search Marketing.

This works with marketers to place adverts on search engines, and is a market that Google says it has no interest in.

In an official Google blog, Tom Phillips, director of DoubleClick Integration, writes: "It is clear to us that we do not want to be in the search engine marketing business".

"At Google, maintaining objectivity in both search and advertising is paramount to our mission and core to the trust we ask from our users."

Industry watchers maintain that the decision to sell off Performics Search Marketing makes good business sense and that Google's primary focus is to get paid as much as possible for the adverts that appear on its pages.

Rumours are circulating that Google is already in talks with a third party to sell the business.