Qualcomm's rivals were ordered to provide details of the company's licensing programme to the European Commission (EC) by mid-May, as part of an antitrust probe of the U.S. chip maker.
The EC sent out questionnaires to competitors last week as part of an investigation opened in October 2014, Reuters reported citing a document associated with the investigation.
Included in the document are questions relating to the way device makers are allowed access to Qualcomm patents, cross-licensing deals, and agreements between patent holders not to enforce patent rights.
The objective of the questionnaires is to provide the EC with key information in a probe that centres on Qualcomm's marketing and sale of chipsets, and financial incentives offered by the chip maker including rebates, Reuters reported.
Qualcomm's recent fiscal Q2 2015 earnings statement, which covers calendar Q1, revealed the company still derives the bulk of its revenues from chip sales. Out of total revenues of $6.8 billion (€6 billion) in the quarter, $4.4 billion came from baseband chip sales, with $2.4 billion coming from patent licensing.
The EC probe is the latest in a series of antitrust investigations opened into Qualcomm globally.
In February, South Korea's Fair Trade Commission opened a probe into whether Qualcomm abused its dominant position in the market, sister publication FierceWireless reported. That investigation was started just a matter of days after the chip maker settled a similar investigation by China's National Development and Reform Commission by agreeing to pay a $975 million fine.
The company also faced scrutiny in its domestic market. In November Qualcomm revealed that its licensing terms had been investigated by the U.S. Federal Trade Commission, which was concerned the company had breached regulations covering the licensing of so-called 'essential' patents.
Regulators typically require holders of essential patents to license them on fair, reasonable and non-discriminatory (FRAND) terms.
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