The European Commission (EC) is extending an investigation into Google’s business practices around Android by sending out new requests for information to handset makers and other involved parties, according to The Wall Street Journal.

The move comes a year after a group of companies including Microsoft and Nokia filed an antitrust complaint with the EU, alleging that Google’s mobile apps are given an unfair advantage by being bundled with the Android OS.

The group — collectively known as FairSearch — stated that while the core Android OS is free, device vendors who want to licence Google’s apps such as Maps, YouTube and Google Play must include the entire Google Apps suite and give it “prominent default placement on the phone”.

A source told The Wall Street Journal that the latest inquiry is not yet a formal investigation.

The complaint in May 2013 also said Google’s approach of offering Android “below cost” and its “predatory distribution” of the OS makes it difficult for competing software makers to recoup their investments. The European Union was reported soon after to be investigating the claims.

More recently, Portugal-based app store provider Aptoide said in June that it had filed a complaint with EU regulators, claiming that Google encourages Android users to use the Play store over competing portals. Aptoide plans to join forces with other independent app stores in relation to the issue.

Android is just one part of Google’s activities that the European Commission is looking at, with visibility of Google services in search results and an auction mechanism used by other companies to secure a better placement on a search page also being investigated.

Google reached a settlement with the European Commission earlier this year in which it agreed to alter search results to avoid a fine that was equivalent to 10 per cent of global revenue.

There has been opposition to the proposed settlement from European politicians and from companies it is meant to help.

A Google spokesperson told The Wall Street Journal that the company made “significant changes” to address the EC’s concerns “by greatly increasing the visibility of rival services and addressing other specific issues”.