* European Commission has received several complaints

* Google's non-search services such as Google+, YouTube under fire

By Francesco Guarascio and Foo Yun Chee

BRUSSELS, Sept 23 (Reuters) - Google Inc, the target of an EU antitrust investigation into its internet search engine, may face further scrutiny over its other services following several complaints, Europe's antitrust chief said on Tuesday.

European Competition Commissioner Joaquin Almunia said this meant Google could end up a bigger case than Microsoft Corp , which found itself embroiled in a decade-long battle with the EU watchdog and was hit with more than 2.2 billion euros ($2.8 billion) in fines.

"We have received complaints on the possible diversion of internet traffic towards Google services which are not search services, so this is a possible third investigation concerning Google," Almunia told a European Parliament hearing.

Google spokesman Al Verney said in response: "We continue to work with the European Commission to resolve their concerns."

Almunia, who is scheduled to leave office by the end of October, did not provide any further details. It was not clear if he would open a case or leave it to his successor Margrethe Vestager.

In June, he said companies including European publishers, a telecoms operator, an association of picture industries and photo libraries as well as an advertising platform had complained about Google leveraging its dominance to promote its social network Google+ and its online video website YouTube.

Almunia also reiterated previous comments on a possible investigation into Google's Android mobile operating system, the most popular in the world and also the subject of several complaints.

Two weeks ago, Almunia said he would not be able to wrap up before leaving office the four-year-old probe into accusations that Google squeezed out rivals in internet search results following fresh studies and arguments from complainants such as Microsoft. (1 US dollar = 0.7776 euro) (Reporting by Foo Yun Chee; Editing by David Holmes)

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