Competition regulators in Asia and Europe are ratcheting up the pressure on Google over charges of unfairly using its search dominance to compete with local rivals.

In Seoul, the Korean Fair Trade Commission, that country's antitrust agency, raided Google's offices this week, according to MLex, a subscription-only newsletter that focuses on European regulatory agencies.The agency raided Google's Seoul office last September, seeking information in its investigation of allegations that Google limits access to rival search engines on its Android mobile operating system.

And in Brussels, the European Union Competition Commissioner Joaquin Almunia sent a letter to Google giving it until July 2 to make its settlement offer to the agency to address its concerns that the search giant has abused its dominant market position, according to the same MLex report. Almunia said during a press conference last week that he hoped Google would offer concessions within "a matter of weeks," but did not give a specific deadline.

Google declined to comment on the raid or Almunia's ultimatum.

"We will of course continue cooperating with this and other government inquiries," the company said in a statement.

In Korea, two local Internet companies -- NHN, which operates the Naver search engine, and Daum Comminications -- asked the antitrust agency a year ago to investigate Google's use of Android to build its search business. The Korean companies have claimed that Google is pressuring smartphone makers and mobile carriers to not pre-load devices with search engines from Naver and Daum.

According to the MLex report, the agency's raid of Google's offices took place Monday and Tuesday.

The investigation in Europe focuses specifically on Google's tactics with regard to Web search. There, Almunia has said that Google has unfairly used its search dominance to favor its own sites, such as Google Maps, over rival services when responding to search queries. He also said that Google may be scraping original content from other sites, such as user review services, and using it in results without prior authorization.

If Google doesn't offer concessions addressing Almunia's concerns, he wrote that the commission will move forward with its investigation, which could lead to it issuing a statement of objections, the European Union's process of filing formal charges against the company.